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• Can spliting an access database cause printer and reporting issues?

  - by leeand00

  We have a setup in which our users log into an access database using MS Access 2003 over an RDP connection. The user's login to their own machines first using a roaming profile. They then click an rdp connection file on the desktop and login to the remote server, via RDP, where they use MS Access as the shell; they don't have any access to any of explorer.exe features such as the start menu. The database they are logging into is more of an application, and provides functionality for entering data, querying data, and running reports via form based menus. It all worked pretty well until we split the database as it was nearing 2GBs in size. We moved out the payroll data into a separate partition, a database with the same name in a different folder, both of them on the server. Only two tables were moved into this new database partition, and they were re-linked as external tables in the new partition. Now while everything appears to be working fine data-wise after the split, there's a new issue when our users login via RDP and attempt to run reports: often the report will not display and instead the user sees an error about the click event of the form. At first I didn't even know it was printer-related, as we didn't really change anything related to the printers as far as I knew. Confused about the error, I talked to the guy who previously worked here and who was in charge of splitting the database, and he told me to tell the users to set their default printers (on their local machines, not on the server) to the "printer" Microsoft XPS Document Writer which isn't a physical printer at all. This allowed the user's to display their reports, but if they want to print out reports, they are required to go to the File menu and select Print, clicking the print icon on the toolbar takes them to a Save As... dialog as would be expected when using the Microsoft XPS Document Writer as your default printer. It's easy to tell if the user is having a problem because a quick mouseover of the printer icon will yield a tooltip of (none) when they cannot access their reports, and a tooltip of Microsoft XPS Document Writer when they can view the reports. If the user's printer is set to anything other than Microsoft XPS Document Writer as the default on their local machine, then (none) is always displayed when they rdp to the database. The RDP settings are setup to transfer the local printer to the server. Telling the users to do this to print has been more of a band-aid on the whole situation until we find a better solution and an explanation as to why splitting a database would prevent users from printing or even viewing access database reports. Which is why I'm here asking this question. Also of note all the printers on the network now show up on the server so that when the users do click File->Print to print their reports on a physical printer, they have to look through a huge list of printers to find theirs in the dropdown. So the little band-aid fix we have is not ideal. Previously, only the printers on the user's local machine displayed here, and not all the printers on the network. My co-worker seems to think this has something to do with permissions, I personally think it has to do with roaming profiles, and Group Policies which is what I've been reading up on. I really don't know how to fix this or how it is related to splitting the database.

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• Windows 7 disk errors after a few hours of runtime

  - by GFK

  I'm having trouble understanding what is going on with my work PC. Whenever I boot it, it runs fine for a while, then starts to randomly show disk errors. The displayed error often contains the message "not enough storage is available to process this command", although depending on the application that fails it can be different. This has happened for weeks now and is getting worse. This is what troubles me: It never seems to impact critical parts of the system (no BSOD, no freeze). Only some applications seem impacted, refusing to function correctly after a while: Outlook 2010 cannot download RSS feeds anymore, Firefox 6 or IE9 cannot download anything bigger than 3MB without failing, Windows Update fails, all msi installers fail, Visual Studio 2010 starts failing in weird manners... It only happens after a while using it (typically 3 hours, but it seems that installing a program or compiling several times makes it shorter) Rebooting solves it (temporarily). The system: The OS is Windows 7 Pro Spanish SP1, 32 bits The system is an HP Compaq 6000 Pro with 4 GB memory (only 3.4GB usable since the system is 32bit), one 500GB hard drive. Installed applications include: Visual Studio 2010, SQL Server 2008 R2, VMWare Workstation 7, Microsoft Security Essentials, Office 2010. Shutting down all related services and processes doesn't seem to change anything. The diagnostics I've run so far: Hard drive : 465GB, 165GB free Process Explorer : physical and virtual memory seem ok (pagefile is 5.3GB, physical memory usage 70%, system commit 39%) Windows Memory diagnostic tool: OK CHKDSK returned: 488282111 KB total disk space. 281668248 KB in 265779 files. 150188 KB in 62949 indexes. 0 KB in bad sectors. 571755 KB in use by the system. The log file has occupied 65536 kilobytes. 205891920 KB available on disk. For non-spanish speakers, that means all ok. SMART diagnostic tools (DiskCheckup) report all values normal. temperatures are in the normal range (HWinfo). The event viewer doesn't seem to contain any significant message. ran CCleaner 3, without any noticeable effect. I was thinking about some file number limit (between Visual Studio projects and other applications, there are around 300.000 files on the hard drive), but I couldn't find any. It's possible there is something related with the use of the temporary folders (it's the only explanation I have for why applications fail but Windows doesn't), but I cannot confirm that. Only thing I cannot find out is if chkdsk reporting 65MB for the log is normal. It seems since Vista it always reports this. Any other cleaning/diagnostic tool you might know of? Edit: I ran several other tools since I first published the question: Seagate SeaTools (the HD manufacturer's analysis tool): complete test run OK. Intel Rapid 10.1 (the HD controller manufacturer's troubleshooting tool): the HD's ok. Microsoft Desktop Heap Monitor: Desktop Heap Information Monitor Tool (Version 8.1.2925.0) Copyright (c) Microsoft Corporation. All rights reserved. Session ID: 1 Total Desktop: ( 46464 KB - 11 desktops) WinStation\Desktop Heap Size(KB) Used Rate(%) WinSta0\Winlogon (s1) 128 3.6 WinSta0\Disconnect (s1) 64 3.8 WinSta0\Default (s1) 20480 3.0 msswindowstation\mssrestricteddesk (s0) 1024 0.2 __X78B95_89_IW__A8D9S1_42_ID (s0) 1024 0.2 Service-0x0-3e5$\Default (s0) 1024 0.6 Service-0x0-3e4$\Default (s0) 1024 0.3 Service-0x0-3e7$\Default (s0) 1024 2.1 WinSta0\Winlogon (s0) 128 1.9 WinSta0\Disconnect (s0) 64 3.8 WinSta0\Default (s0) 20480 0.0 All ok, desktop heap usage < 5% Edit 2: I tried totally resetting my account by creating a new one, logging under this new one and delete the first one (local rights and files), then logging back with this deleted account (it is a domain account). No luck. Also, I found out often the error is "not enough storage is available to process this command". Searching on the internet, I found an old troubleshooting tip (setting a registry key to raise the IRP stack limit, whatever it is) which did not change anything.

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• suddenly can't connect to router

  - by Khoi

  I was just downloading some stuff in ubuntu and snap, the connection cut and I can't even connect to my router. And the router, it still works fine, my laptop can connect wirelessly to it as usual. But my main computer (which connects to it directly through cable) can't even ping it. Here is my ipconfig: Windows IP Configuration Host Name . . . . . . . . . . . . : vento Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Ethernet adapter Local Area Connection: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : Realtek RTL8169/8110 Family Gigabit Ethernet NIC Physical Address. . . . . . . . . : 00-19-DB-4E-6C-56 Ethernet adapter {15B1F740-2F35-4FE4-9FEE-4052AFBAD096}: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : Anchorfree HSS Adapter - Packet Sche duler Miniport Physical Address. . . . . . . . . : 00-FF-15-B1-F7-40

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• The Proper Use of the VM Role in Windows Azure

  - by BuckWoody

  At the Professional Developer’s Conference (PDC) in 2010 we announced an addition to the Computational Roles in Windows Azure, called the VM Role. This new feature allows a great deal of control over the applications you write, but some have confused it with our full infrastructure offering in Windows Hyper-V. There is a proper architecture pattern for both of them. Virtualization Virtualization is the process of taking all of the hardware of a physical computer and replicating it in software alone. This means that a single computer can “host” or run several “virtual” computers. These virtual computers can run anywhere - including at a vendor’s location. Some companies refer to this as Cloud Computing since the hardware is operated and maintained elsewhere. IaaS The more detailed definition of this type of computing is called Infrastructure as a Service (Iaas) since it removes the need for you to maintain hardware at your organization. The operating system, drivers, and all the other software required to run an application are still under your control and your responsibility to license, patch, and scale. Microsoft has an offering in this space called Hyper-V, that runs on the Windows operating system. Combined with a hardware hosting vendor and the System Center software to create and deploy Virtual Machines (a process referred to as provisioning), you can create a Cloud environment with full control over all aspects of the machine, including multiple operating systems if you like. Hosting machines and provisioning them at your own buildings is sometimes called a Private Cloud, and hosting them somewhere else is often called a Public Cloud. State-ful and Stateless Programming This paradigm does not create a new, scalable way of computing. It simply moves the hardware away. The reason is that when you limit the Cloud efforts to a Virtual Machine, you are in effect limiting the computing resources to what that single system can provide. This is because much of the software developed in this environment maintains “state” - and that requires a little explanation. “State-ful programming” means that all parts of the computing environment stay connected to each other throughout a compute cycle. The system expects the memory, CPU, storage and network to remain in the same state from the beginning of the process to the end. You can think of this as a telephone conversation - you expect that the other person picks up the phone, listens to you, and talks back all in a single unit of time. In “Stateless” computing the system is designed to allow the different parts of the code to run independently of each other. You can think of this like an e-mail exchange. You compose an e-mail from your system (it has the state when you’re doing that) and then you walk away for a bit to make some coffee. A few minutes later you click the “send” button (the network has the state) and you go to a meeting. The server receives the message and stores it on a mail program’s database (the mail server has the state now) and continues working on other mail. Finally, the other party logs on to their mail client and reads the mail (the other user has the state) and responds to it and so on. These events might be separated by milliseconds or even days, but the system continues to operate. The entire process doesn’t maintain the state, each component does. This is the exact concept behind coding for Windows Azure. The stateless programming model allows amazing rates of scale, since the message (think of the e-mail) can be broken apart by multiple programs and worked on in parallel (like when the e-mail goes to hundreds of users), and only the order of re-assembling the work is important to consider. For the exact same reason, if the system makes copies of those running programs as Windows Azure does, you have built-in redundancy and recovery. It’s just built into the design. The Difference Between Infrastructure Designs and Platform Designs When you simply take a physical server running software and virtualize it either privately or publicly, you haven’t done anything to allow the code to scale or have recovery. That all has to be handled by adding more code and more Virtual Machines that have a slight lag in maintaining the running state of the system. Add more machines and you get more lag, so the scale is limited. This is the primary limitation with IaaS. It’s also not as easy to deploy these VM’s, and more importantly, you’re often charged on a longer basis to remove them. your agility in IaaS is more limited. Windows Azure is a Platform - meaning that you get objects you can code against. The code you write runs on multiple nodes with multiple copies, and it all works because of the magic of Stateless programming. you don’t worry, or even care, about what is running underneath. It could be Windows (and it is in fact a type of Windows Server), Linux, or anything else - but that' isn’t what you want to manage, monitor, maintain or license. You don’t want to deploy an operating system - you want to deploy an application. You want your code to run, and you don’t care how it does that. Another benefit to PaaS is that you can ask for hundreds or thousands of new nodes of computing power - there’s no provisioning, it just happens. And you can stop using them quicker - and the base code for your application does not have to change to make this happen. Windows Azure Roles and Their Use If you need your code to have a user interface, in Visual Studio you add a Web Role to your project, and if the code needs to do work that doesn’t involve a user interface you can add a Worker Role. They are just containers that act a certain way. I’ll provide more detail on those later. Note: That’s a general description, so it’s not entirely accurate, but it’s accurate enough for this discussion. So now we’re back to that VM Role. Because of the name, some have mistakenly thought that you can take a Virtual Machine running, say Linux, and deploy it to Windows Azure using this Role. But you can’t. That’s not what it is designed for at all. If you do need that kind of deployment, you should look into Hyper-V and System Center to create the Private or Public Infrastructure as a Service. What the VM Role is actually designed to do is to allow you to have a great deal of control over the system where your code will run. Let’s take an example. You’ve heard about Windows Azure, and Platform programming. You’re convinced it’s the right way to code. But you have a lot of things you’ve written in another way at your company. Re-writing all of your code to take advantage of Windows Azure will take a long time. Or perhaps you have a certain version of Apache Web Server that you need for your code to work. In both cases, you think you can (or already have) code the the software to be “Stateless”, you just need more control over the place where the code runs. That’s the place where a VM Role makes sense. Recap Virtualizing servers alone has limitations of scale, availability and recovery. Microsoft’s offering in this area is Hyper-V and System Center, not the VM Role. The VM Role is still used for running Stateless code, just like the Web and Worker Roles, with the exception that it allows you more control over the environment of where that code runs.

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• SQL SERVER – SSMS: Disk Usage Report

  - by Pinal Dave

  Let us start with humor!  I think we the series on various reports, we come to a logical point. We covered all the reports at server level. This means the reports we saw were targeted towards activities that are related to instance level operations. These are mostly like how a doctor diagnoses a patient. At this point I am reminded of a dialog which I read somewhere: Patient: Doc, It hurts when I touch my head. Doc: Ok, go on. What else have you experienced? Patient: It hurts even when I touch my eye, it hurts when I touch my arms, it even hurts when I touch my feet, etc. Doc: Hmmm … Patient: I feel it hurts when I touch anywhere in my body. Doc: Ahh … now I get it. You need a plaster to your finger John. Sometimes the server level gives an indicator to what is happening in the system, but we need to get to the root cause for a specific database. So, this is the first blog in series where we would start discussing about database level reports. To launch database level reports, expand selected server in Object Explorer, expand the Databases folder, and then right-click any database for which we want to look at reports. From the menu, select Reports, then Standard Reports, and then any of database level reports. In this blog, we would talk about four “disk” reports because they are similar: Disk Usage Disk Usage by Top Tables Disk Usage by Table Disk Usage by Partition Disk Usage This report shows multiple information about the database. Let us discuss them one by one.  We have divided the output into 5 different sections. Section 1 shows the high level summary of the database. It shows the space used by database files (mdf and ldf). Under the hood, the report uses, various DMVs and DBCC Commands, it is using sys.data_spaces and DBCC SHOWFILESTATS. Section 2 and 3 are pie charts. One for data file allocation and another for the transaction log file. Pie chart for “Data Files Space Usage (%)” shows space consumed data, indexes, allocated to the SQL Server database, and unallocated space which is allocated to the SQL Server database but not yet filled with anything. “Transaction Log Space Usage (%)” used DBCC SQLPERF (LOGSPACE) and shows how much empty space we have in the physical transaction log file. Section 4 shows the data from Default Trace and looks at Event IDs 92, 93, 94, 95 which are for “Data File Auto Grow”, “Log File Auto Grow”, “Data File Auto Shrink” and “Log File Auto Shrink” respectively. Here is an expanded view for that section. If default trace is not enabled, then this section would be replaced by the message “Trace Log is disabled” as highlighted below. Section 5 of the report uses DBCC SHOWFILESTATS to get information. Here is the enhanced version of that section. This shows the physical layout of the file. In case you have In-Memory Objects in the database (from SQL Server 2014), then report would show information about those as well. Here is the screenshot taken for a different database, which has In-Memory table. I have highlighted new things which are only shown for in-memory database. The new sections which are highlighted above are using sys.dm_db_xtp_checkpoint_files, sys.database_files and sys.data_spaces. The new type for in-memory OLTP is ‘FX’ in sys.data_space. The next set of reports is targeted to get information about a table and its storage. These reports can answer questions like: Which is the biggest table in the database? How many rows we have in table? Is there any table which has a lot of reserved space but its unused? Which partition of the table is having more data? Disk Usage by Top Tables This report provides detailed data on the utilization of disk space by top 1000 tables within the Database. The report does not provide data for memory optimized tables. Disk Usage by Table This report is same as earlier report with few difference. First Report shows only 1000 rows First Report does order by values in DMV sys.dm_db_partition_stats whereas second one does it based on name of the table. Both of the reports have interactive sort facility. We can click on any column header and change the sorting order of data. Disk Usage by Partition This report shows the distribution of the data in table based on partition in the table. This is so similar to previous output with the partition details now. Here is the query taken from profiler. SELECT row_number() OVER (ORDER BY a1.used_page_count DESC, a1.index_id) AS row_number ,      (dense_rank() OVER (ORDER BY a5.name, a2.name))%2 AS l1 ,      a1.OBJECT_ID ,      a5.name AS [schema] ,       a2.name ,       a1.index_id ,       a3.name AS index_name ,       a3.type_desc ,       a1.partition_number ,       a1.used_page_count * 8 AS total_used_pages ,       a1.reserved_page_count * 8 AS total_reserved_pages ,       a1.row_count FROM sys.dm_db_partition_stats a1 INNER JOIN sys.all_objects a2  ON ( a1.OBJECT_ID = a2.OBJECT_ID) AND a1.OBJECT_ID NOT IN (SELECT OBJECT_ID FROM sys.tables WHERE is_memory_optimized = 1) INNER JOIN sys.schemas a5 ON (a5.schema_id = a2.schema_id) LEFT OUTER JOIN  sys.indexes a3  ON ( (a1.OBJECT_ID = a3.OBJECT_ID) AND (a1.index_id = a3.index_id) ) WHERE (SELECT MAX(DISTINCT partition_number) FROM sys.dm_db_partition_stats a4 WHERE (a4.OBJECT_ID = a1.OBJECT_ID)) >= 1 AND a2.TYPE <> N'S' AND  a2.TYPE <> N'IT' ORDER BY a5.name ASC, a2.name ASC, a1.index_id, a1.used_page_count DESC, a1.partition_number Using all of the above reports, you should be able to get the usage of database files and also space used by tables. I think this is too much disk information for a single blog and I hope you have used them in the past to get data. Do let me know if you found anything interesting using these reports in your environments. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL Tagged: SQL Reports

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• The blocking nature of aggregates

  - by Rob Farley

  I wrote a post recently about how query tuning isn’t just about how quickly the query runs – that if you have something (such as SSIS) that is consuming your data (and probably introducing a bottleneck), then it might be more important to have a query which focuses on getting the first bit of data out. You can read that post here.  In particular, we looked at two operators that could be used to ensure that a query returns only Distinct rows. and The Sort operator pulls in all the data, sorts it (discarding duplicates), and then pushes out the remaining rows. The Hash Match operator performs a Hashing function on each row as it comes in, and then looks to see if it’s created a Hash it’s seen before. If not, it pushes the row out. The Sort method is quicker, but has to wait until it’s gathered all the data before it can do the sort, and therefore blocks the data flow. But that was my last post. This one’s a bit different. This post is going to look at how Aggregate functions work, which ties nicely into this month’s T-SQL Tuesday. I’ve frequently explained about the fact that DISTINCT and GROUP BY are essentially the same function, although DISTINCT is the poorer cousin because you have less control over it, and you can’t apply aggregate functions. Just like the operators used for Distinct, there are different flavours of Aggregate operators – coming in blocking and non-blocking varieties. The example I like to use to explain this is a pile of playing cards. If I’m handed a pile of cards and asked to count how many cards there are in each suit, it’s going to help if the cards are already ordered. Suppose I’m playing a game of Bridge, I can easily glance at my hand and count how many there are in each suit, because I keep the pile of cards in order. Moving from left to right, I could tell you I have four Hearts in my hand, even before I’ve got to the end. By telling you that I have four Hearts as soon as I know, I demonstrate the principle of a non-blocking operation. This is known as a Stream Aggregate operation. It requires input which is sorted by whichever columns the grouping is on, and it will release a row as soon as the group changes – when I encounter a Spade, I know I don’t have any more Hearts in my hand. Alternatively, if the pile of cards are not sorted, I won’t know how many Hearts I have until I’ve looked through all the cards. In fact, to count them, I basically need to put them into little piles, and when I’ve finished making all those piles, I can count how many there are in each. Because I don’t know any of the final numbers until I’ve seen all the cards, this is blocking. This performs the aggregate function using a Hash Match. Observant readers will remember this from my Distinct example. You might remember that my earlier Hash Match operation – used for Distinct Flow – wasn’t blocking. But this one is. They’re essentially doing a similar operation, applying a Hash function to some data and seeing if the set of values have been seen before, but before, it needs more information than the mere existence of a new set of values, it needs to consider how many of them there are. A lot is dependent here on whether the data coming out of the source is sorted or not, and this is largely determined by the indexes that are being used. If you look in the Properties of an Index Scan, you’ll be able to see whether the order of the data is required by the plan. A property called Ordered will demonstrate this. In this particular example, the second plan is significantly faster, but is dependent on having ordered data. In fact, if I force a Stream Aggregate on unordered data (which I’m doing by telling it to use a different index), a Sort operation is needed, which makes my plan a lot slower. This is all very straight-forward stuff, and information that most people are fully aware of. I’m sure you’ve all read my good friend Paul White (@sql_kiwi)’s post on how the Query Optimizer chooses which type of aggregate function to apply. But let’s take a look at SQL Server Integration Services. SSIS gives us a Aggregate transformation for use in Data Flow Tasks, but it’s described as Blocking. The definitive article on Performance Tuning SSIS uses Sort and Aggregate as examples of Blocking Transformations. I’ve just shown you that Aggregate operations used by the Query Optimizer are not always blocking, but that the SSIS Aggregate component is an example of a blocking transformation. But is it always the case? After all, there are plenty of SSIS Performance Tuning talks out there that describe the value of sorted data in Data Flow Tasks, describing the IsSorted property that can be set through the Advanced Editor of your Source component. And so I set about testing the Aggregate transformation in SSIS, to prove for sure whether providing Sorted data would let the Aggregate transform behave like a Stream Aggregate. (Of course, I knew the answer already, but it helps to be able to demonstrate these things). A query that will produce a million rows in order was in order. Let me rephrase. I used a query which produced the numbers from 1 to 1000000, in a single field, ordered. The IsSorted flag was set on the source output, with the only column as SortKey 1. Performing an Aggregate function over this (counting the number of rows per distinct number) should produce an additional column with 1 in it. If this were being done in T-SQL, the ordered data would allow a Stream Aggregate to be used. In fact, if the Query Optimizer saw that the field had a Unique Index on it, it would be able to skip the Aggregate function completely, and just insert the value 1. This is a shortcut I wouldn’t be expecting from SSIS, but certainly the Stream behaviour would be nice. Unfortunately, it’s not the case. As you can see from the screenshots above, the data is pouring into the Aggregate function, and not being released until all million rows have been seen. It’s not doing a Stream Aggregate at all. This is expected behaviour. (I put that in bold, because I want you to realise this.) An SSIS transformation is a piece of code that runs. It’s a physical operation. When you write T-SQL and ask for an aggregation to be done, it’s a logical operation. The physical operation is either a Stream Aggregate or a Hash Match. In SSIS, you’re telling the system that you want a generic Aggregation, that will have to work with whatever data is passed in. I’m not saying that it wouldn’t be possible to make a sometimes-blocking aggregation component in SSIS. A Custom Component could be created which could detect whether the SortKeys columns of the input matched the Grouping columns of the Aggregation, and either call the blocking code or the non-blocking code as appropriate. One day I’ll make one of those, and publish it on my blog. I’ve done it before with a Script Component, but as Script components are single-use, I was able to handle the data knowing everything about my data flow already. As per my previous post – there are a lot of aspects in which tuning SSIS and tuning execution plans use similar concepts. In both situations, it really helps to have a feel for what’s going on behind the scenes. Considering whether an operation is blocking or not is extremely relevant to performance, and that it’s not always obvious from the surface. In a future post, I’ll show the impact of blocking v non-blocking and synchronous v asynchronous components in SSIS, using some of LobsterPot’s Script Components and Custom Components as examples. When I get that sorted, I’ll make a Stream Aggregate component available for download.

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• The blocking nature of aggregates

  - by Rob Farley

  I wrote a post recently about how query tuning isn’t just about how quickly the query runs – that if you have something (such as SSIS) that is consuming your data (and probably introducing a bottleneck), then it might be more important to have a query which focuses on getting the first bit of data out. You can read that post here.  In particular, we looked at two operators that could be used to ensure that a query returns only Distinct rows. and The Sort operator pulls in all the data, sorts it (discarding duplicates), and then pushes out the remaining rows. The Hash Match operator performs a Hashing function on each row as it comes in, and then looks to see if it’s created a Hash it’s seen before. If not, it pushes the row out. The Sort method is quicker, but has to wait until it’s gathered all the data before it can do the sort, and therefore blocks the data flow. But that was my last post. This one’s a bit different. This post is going to look at how Aggregate functions work, which ties nicely into this month’s T-SQL Tuesday. I’ve frequently explained about the fact that DISTINCT and GROUP BY are essentially the same function, although DISTINCT is the poorer cousin because you have less control over it, and you can’t apply aggregate functions. Just like the operators used for Distinct, there are different flavours of Aggregate operators – coming in blocking and non-blocking varieties. The example I like to use to explain this is a pile of playing cards. If I’m handed a pile of cards and asked to count how many cards there are in each suit, it’s going to help if the cards are already ordered. Suppose I’m playing a game of Bridge, I can easily glance at my hand and count how many there are in each suit, because I keep the pile of cards in order. Moving from left to right, I could tell you I have four Hearts in my hand, even before I’ve got to the end. By telling you that I have four Hearts as soon as I know, I demonstrate the principle of a non-blocking operation. This is known as a Stream Aggregate operation. It requires input which is sorted by whichever columns the grouping is on, and it will release a row as soon as the group changes – when I encounter a Spade, I know I don’t have any more Hearts in my hand. Alternatively, if the pile of cards are not sorted, I won’t know how many Hearts I have until I’ve looked through all the cards. In fact, to count them, I basically need to put them into little piles, and when I’ve finished making all those piles, I can count how many there are in each. Because I don’t know any of the final numbers until I’ve seen all the cards, this is blocking. This performs the aggregate function using a Hash Match. Observant readers will remember this from my Distinct example. You might remember that my earlier Hash Match operation – used for Distinct Flow – wasn’t blocking. But this one is. They’re essentially doing a similar operation, applying a Hash function to some data and seeing if the set of values have been seen before, but before, it needs more information than the mere existence of a new set of values, it needs to consider how many of them there are. A lot is dependent here on whether the data coming out of the source is sorted or not, and this is largely determined by the indexes that are being used. If you look in the Properties of an Index Scan, you’ll be able to see whether the order of the data is required by the plan. A property called Ordered will demonstrate this. In this particular example, the second plan is significantly faster, but is dependent on having ordered data. In fact, if I force a Stream Aggregate on unordered data (which I’m doing by telling it to use a different index), a Sort operation is needed, which makes my plan a lot slower. This is all very straight-forward stuff, and information that most people are fully aware of. I’m sure you’ve all read my good friend Paul White (@sql_kiwi)’s post on how the Query Optimizer chooses which type of aggregate function to apply. But let’s take a look at SQL Server Integration Services. SSIS gives us a Aggregate transformation for use in Data Flow Tasks, but it’s described as Blocking. The definitive article on Performance Tuning SSIS uses Sort and Aggregate as examples of Blocking Transformations. I’ve just shown you that Aggregate operations used by the Query Optimizer are not always blocking, but that the SSIS Aggregate component is an example of a blocking transformation. But is it always the case? After all, there are plenty of SSIS Performance Tuning talks out there that describe the value of sorted data in Data Flow Tasks, describing the IsSorted property that can be set through the Advanced Editor of your Source component. And so I set about testing the Aggregate transformation in SSIS, to prove for sure whether providing Sorted data would let the Aggregate transform behave like a Stream Aggregate. (Of course, I knew the answer already, but it helps to be able to demonstrate these things). A query that will produce a million rows in order was in order. Let me rephrase. I used a query which produced the numbers from 1 to 1000000, in a single field, ordered. The IsSorted flag was set on the source output, with the only column as SortKey 1. Performing an Aggregate function over this (counting the number of rows per distinct number) should produce an additional column with 1 in it. If this were being done in T-SQL, the ordered data would allow a Stream Aggregate to be used. In fact, if the Query Optimizer saw that the field had a Unique Index on it, it would be able to skip the Aggregate function completely, and just insert the value 1. This is a shortcut I wouldn’t be expecting from SSIS, but certainly the Stream behaviour would be nice. Unfortunately, it’s not the case. As you can see from the screenshots above, the data is pouring into the Aggregate function, and not being released until all million rows have been seen. It’s not doing a Stream Aggregate at all. This is expected behaviour. (I put that in bold, because I want you to realise this.) An SSIS transformation is a piece of code that runs. It’s a physical operation. When you write T-SQL and ask for an aggregation to be done, it’s a logical operation. The physical operation is either a Stream Aggregate or a Hash Match. In SSIS, you’re telling the system that you want a generic Aggregation, that will have to work with whatever data is passed in. I’m not saying that it wouldn’t be possible to make a sometimes-blocking aggregation component in SSIS. A Custom Component could be created which could detect whether the SortKeys columns of the input matched the Grouping columns of the Aggregation, and either call the blocking code or the non-blocking code as appropriate. One day I’ll make one of those, and publish it on my blog. I’ve done it before with a Script Component, but as Script components are single-use, I was able to handle the data knowing everything about my data flow already. As per my previous post – there are a lot of aspects in which tuning SSIS and tuning execution plans use similar concepts. In both situations, it really helps to have a feel for what’s going on behind the scenes. Considering whether an operation is blocking or not is extremely relevant to performance, and that it’s not always obvious from the surface. In a future post, I’ll show the impact of blocking v non-blocking and synchronous v asynchronous components in SSIS, using some of LobsterPot’s Script Components and Custom Components as examples. When I get that sorted, I’ll make a Stream Aggregate component available for download.

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• SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

  - by pinaldave

  I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• Running Solaris 11 as a control domain on a T2000

  - by jsavit

  There is increased adoption of Oracle Solaris 11, and many customers are deploying it on systems that previously ran Solaris 10. That includes older T1-processor based systems like T1000 and T2000. Even though they are old (from 2005) and don't have the performance of current SPARC servers, they are still functional, stable servers that customers continue to operate. One reason to install Solaris 11 on them is that older machines are attractive for testing OS upgrades before updating current, production systems. Normally this does not present a challenge, because Solaris 11 runs on any T-series or M-series SPARC server. One scenario adds a complication: running Solaris 11 in a control domain on a T1000 or T2000 hosting logical domains. Solaris 11 pre-installed Oracle VM Server for SPARC incompatible with T1 Unlike Solaris 10, Solaris 11 comes with Oracle VM Server for SPARC preinstalled. The ldomsmanager package contains the logical domains manager for Oracle VM Server for SPARC 2.2, which requires a SPARC T2, T2+, T3, or T4 server. It does not work with T1-processor systems, which are only supported by LDoms Manager 1.2 and earlier. The following screenshot shows what happens (bold font) if you try to use Oracle VM Server for SPARC 2.x commands in a Solaris 11 control domain. The commands were issued in a control domain on a T2000 that previously ran Solaris 10. We also display the version of the logical domains manager installed in Solaris 11: root@t2000 psrinfo -vp The physical processor has 4 virtual processors (0-3) UltraSPARC-T1 (chipid 0, clock 1200 MHz) # prtconf|grep T SUNW,Sun-Fire-T200 # ldm -V Failed to connect to logical domain manager: Connection refused # pkg info ldomsmanager Name: system/ldoms/ldomsmanager Summary: Logical Domains Manager Description: LDoms Manager - Virtualization for SPARC T-Series Category: System/Virtualization State: Installed Publisher: solaris Version: 2.2.0.0 Build Release: 5.11 Branch: 0.175.0.8.0.3.0 Packaging Date: May 25, 2012 10:20:48 PM Size: 2.86 MB FMRI: pkg://solaris/system/ldoms/[email protected],5.11-0.175.0.8.0.3.0:20120525T222048Z The 2.2 version of the logical domains manager will have to be removed, and 1.2 installed, in order to use this as a control domain. Preparing to change - create a new boot environment Before doing anything else, lets create a new boot environment: # beadm list BE Active Mountpoint Space Policy Created -- ------ ---------- ----- ------ ------- solaris NR / 2.14G static 2012-09-25 10:32 # beadm create solaris-1 # beadm activate solaris-1 # beadm list BE Active Mountpoint Space Policy Created -- ------ ---------- ----- ------ ------- solaris N / 4.82M static 2012-09-25 10:32 solaris-1 R - 2.14G static 2012-09-29 11:40 # init 0 Normally an init 6 to reboot would have been sufficient, but in the next step I reset the system anyway in order to put the system in factory default mode for a "clean" domain configuration. Preparing to change - reset to factory default There was a leftover domain configuration on the T2000, so I reset it to the factory install state. Since the ldm command is't working yet, it can't be done from the control domain, so I did it by logging onto to the service processor: $ ssh -X admin@t2000-sc Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. Oracle Advanced Lights Out Manager CMT v1.7.9 Please login: admin Please Enter password: ******** sc> showhost Sun-Fire-T2000 System Firmware 6.7.10 2010/07/14 16:35 Host flash versions: OBP 4.30.4.b 2010/07/09 13:48 Hypervisor 1.7.3.c 2010/07/09 15:14 POST 4.30.4.b 2010/07/09 14:24 sc> bootmode config="factory-default" sc> poweroff Are you sure you want to power off the system [y/n]? y SC Alert: SC Request to Power Off Host. SC Alert: Host system has shut down. sc> poweron SC Alert: Host System has Reset At this point I rebooted into the new Solaris 11 boot environment, and Solaris commands showed it was running on the factory default configuration of a single domain owning all 32 CPUs and 32GB of RAM (that's what it looked like in 2005.) # psrinfo -vp The physical processor has 8 cores and 32 virtual processors (0-31) The core has 4 virtual processors (0-3) The core has 4 virtual processors (4-7) The core has 4 virtual processors (8-11) The core has 4 virtual processors (12-15) The core has 4 virtual processors (16-19) The core has 4 virtual processors (20-23) The core has 4 virtual processors (24-27) The core has 4 virtual processors (28-31) UltraSPARC-T1 (chipid 0, clock 1200 MHz) # prtconf|grep Mem Memory size: 32640 Megabytes Note that the older processor has 4 virtual CPUs per core, while current processors have 8 per core. Remove ldomsmanager 2.2 and install the 1.2 version The Solaris 11 pkg command is now used to remove the 2.2 version that shipped with Solaris 11: # pkg uninstall ldomsmanager Packages to remove: 1 Create boot environment: No Create backup boot environment: No Services to change: 2 PHASE ACTIONS Removal Phase 130/130 PHASE ITEMS Package State Update Phase 1/1 Package Cache Update Phase 1/1 Image State Update Phase 2/2 Finally, LDoms 1.2 installed via its install script, the same way it was done years ago: # unzip LDoms-1_2-Integration-10.zip # cd LDoms-1_2-Integration-10/Install/ # ./install-ldm Welcome to the LDoms installer. You are about to install the Logical Domains Manager package that will enable you to create, destroy and control other domains on your system. Given the capabilities of the LDoms domain manager, you can now change the security configuration of this Solaris instance using the Solaris Security Toolkit. ... ... normal install messages omitted ... The Solaris Security Toolkit applies to Solaris 10, and cannot be used in Solaris 11 (in which several things hardened by the Toolkit are already hardened by default), so answer b in the choice below: You are about to install the Logical Domains Manager package that will enable you to create, destroy and control other domains on your system. Given the capabilities of the LDoms domain manager, you can now change the security configuration of this Solaris instance using the Solaris Security Toolkit. Select a security profile from this list: a) Hardened Solaris configuration for LDoms (recommended) b) Standard Solaris configuration c) Your custom-defined Solaris security configuration profile Enter a, b, or c [a]: b ... other install messages omitted for brevity... After install I ensure that the necessary services are enabled, and verify the version of the installed LDoms Manager: # svcs ldmd STATE STIME FMRI online 22:00:36 svc:/ldoms/ldmd:default # svcs vntsd STATE STIME FMRI disabled Aug_19 svc:/ldoms/vntsd:default # ldm -V Logical Domain Manager (v 1.2-debug) Hypervisor control protocol v 1.3 Using Hypervisor MD v 1.1 System PROM: Hypervisor v. 1.7.3. @(#)Hypervisor 1.7.3.c 2010/07/09 15:14\015 OpenBoot v. 4.30.4. @(#)OBP 4.30.4.b 2010/07/09 13:48 Set up control domain and domain services At this point we have a functioning LDoms 1.2 environment that can be configured in the usual fashion. One difference is that LDoms 1.2 behavior had 'delayed configuration mode (as expected) during initial configuration before rebooting the control domain. Another minor difference with a Solaris 11 control domain is that you define virtual switches using the 'vanity name' of the network interface, rather than the hardware driver name as in Solaris 10. # ldm list ------------------------------------------------------------------------------ Notice: the LDom Manager is running in configuration mode. Configuration and resource information is displayed for the configuration under construction; not the current active configuration. The configuration being constructed will only take effect after it is downloaded to the system controller and the host is reset. ------------------------------------------------------------------------------ NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-c-- SP 32 32640M 3.2% 4d 2h 50m # ldm add-vdiskserver primary-vds0 primary # ldm add-vconscon port-range=5000-5100 primary-vcc0 primary # ldm add-vswitch net-dev=net0 primary-vsw0 primary # ldm set-mau 2 primary # ldm set-vcpu 8 primary # ldm set-memory 4g primary # ldm add-config initial # ldm list-spconfig factory-default initial [current] That's it, really. After reboot, we are ready to install guest domains. Summary - new wine in old bottles This example shows that (new) Solaris 11 can be installed on (old) T2000 servers and used as a control domain. The main activity is to remove the preinstalled Oracle VM Server for 2.2 and install Logical Domains 1.2 - the last version of LDoms to support T1-processor systems. I tested Solaris 10 and Solaris 11 guest domains running on this server and they worked without any surprises. This is a viable way to get further into Solaris 11 adoption, even on older T-series equipment.

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• Hard drive mounted at / , duplicate mounted hard drive after using MountManager

  - by HellHarvest

  possible duplicate post I'm running 12.04 64bit. My system is a dual boot for both Ubuntu and Windows7. Both operating systems are sharing the drive named "Elements". My volume named "Elements" is a 1TB SATA NTFS hard drive that shows up twice in the side bar in nautilus. One of the icons is functional and even has the convenient "eject" icon next to it. Below is a picture of the left menu in Nautilus, with System Monitor-File Systems tab open on top of it. Can someone advise me about how to get rid of this extra icon? I think the problem is much more deep-rooted than just a GUI glitch on Nautilus' part. The other icon does nothing but spit out the following error when I click on it (image below). This only happened AFTER I tried using Mount Manager to automate mounting the drive at start up. I've already uninstalled Mount Manager, and restarted, but the problem didn't go away. The hard drive does mount automatically now, so I guess that's cool. But now, every time I boot up now and open Nautilus, BOTH of these icons appear, one of which is fictitious and useless. According to the image above and the outputs of several other commands, it appears to be mounted at / In which case, no matter where I am in Nautilus when I try to click on that icon, of course it will tell me that that drive is in use by another program... Nautilus. I'm afraid of trying to unmount this hard drive (sdb6) because of where it appears to be mounted. I'm kind of a noob, and I have this gut feeling that tells me trying to unmount a drive at / will destroy my entire file system. This fear was further strengthened by the output of "$ fsck" at the very bottom of this post. Error immediately below when that 2nd "Elements" hard drive is clicked in Nautilus: Unable to mount Elements Mount is denied because the NTFS volume is already exclusively opened. The volume may be already mounted, or another software may use it which could be identified for example by the help of the 'fuser' command. It's odd to me that that error message above claims that it's an NTFS volume when everything else tell me that it's an ext4 volume. The actual hard drive "Elements" is in fact an NTFS volume. Here's the output of a few commands and configuration files that may be of interest: $ fuser -a / /: 2120r 2159rc 2160rc 2172r 2178rc 2180rc 2188r 2191rc 2200rc 2203rc 2205rc 2206r 2211r 2212r 2214r 2220r 2228r 2234rc 2246rc 2249rc 2254rc 2260rc 2261r 2262r 2277rc 2287rc 2291rc 2311rc 2313rc 2332rc 2334rc 2339rc 2343rc 2344rc 2352rc 2372rc 2389rc 2422r 2490r 2496rc 2501rc 2566r 2573rc 2581rc 2589rc 2592r 2603r 2611rc 2613rc 2615rc 2678rc 2927r 2981r 3104rc 4156rc 4196rc 4206rc 4213rc 4240rc 4297rc 5032rc 7609r 7613r 7648r 9593rc 18829r 18833r 19776r $ sudo df -h Filesystem Size Used Avail Use% Mounted on /dev/sdb6 496G 366G 106G 78% / udev 2.0G 4.0K 2.0G 1% /dev tmpfs 791M 1.5M 790M 1% /run none 5.0M 0 5.0M 0% /run/lock none 2.0G 672K 2.0G 1% /run/shm /dev/sda1 932G 312G 620G 34% /media/Elements /home/solderblob/.Private 496G 366G 106G 78% /home/solderblob /dev/sdb2 188G 100G 88G 54% /media/A2B24EACB24E852F /dev/sdb1 100M 25M 76M 25% /media/System Reserved $ sudo fdisk -l Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00093cab Device Boot Start End Blocks Id System /dev/sda1 2048 1953519615 976758784 7 HPFS/NTFS/exFAT Disk /dev/sdb: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000e8d9b Device Boot Start End Blocks Id System /dev/sdb1 * 2048 206847 102400 7 HPFS/NTFS/exFAT /dev/sdb2 206848 392378768 196085960+ 7 HPFS/NTFS/exFAT /dev/sdb3 392380414 1465147391 536383489 5 Extended /dev/sdb5 1456762880 1465147391 4192256 82 Linux swap / Solaris /dev/sdb6 392380416 1448374271 527996928 83 Linux /dev/sdb7 1448376320 1456758783 4191232 82 Linux swap / Solaris Partition table entries are not in disk order $ cat /etc/fstab # <file system> <mount point> <type> <options> <dump> <pass> UUID=77039a2a-83d4-47a1-8a8c-a2ec4e4dfd0e / ext4 defaults 0 1 UUID=F6549CC4549C88CF /media/Elements ntfs-3g users 0 0 $ sudo blkid /dev/sda1: LABEL="Elements" UUID="F6549CC4549C88CF" TYPE="ntfs" /dev/sdb1: LABEL="System Reserved" UUID="5CDE130FDE12E156" TYPE="ntfs" /dev/sdb2: UUID="A2B24EACB24E852F" TYPE="ntfs" /dev/sdb6: UUID="77039a2a-83d4-47a1-8a8c-a2ec4e4dfd0e" TYPE="ext4" $ sudo blkid -c /dev/null (appears to be exactly the same as above) /dev/sda1: LABEL="Elements" UUID="F6549CC4549C88CF" TYPE="ntfs" /dev/sdb1: LABEL="System Reserved" UUID="5CDE130FDE12E156" TYPE="ntfs" /dev/sdb2: UUID="A2B24EACB24E852F" TYPE="ntfs" /dev/sdb6: UUID="77039a2a-83d4-47a1-8a8c-a2ec4e4dfd0e" TYPE="ext4" $ mount /dev/sdb6 on / type ext4 (rw) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) /dev/sda1 on /media/Elements type fuseblk (rw,noexec,nosuid,nodev,allow_other,blksize=4096) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) /home/solderblob/.Private on /home/solderblob type ecryptfs (ecryptfs_check_dev_ruid,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs,ecryptfs_sig=76a47b0175afa48d,ecryptfs_fnek_sig=391b2d8b155215f7) gvfs-fuse-daemon on /home/solderblob/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=solderblob) /dev/sdb2 on /media/A2B24EACB24E852F type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096) /dev/sdb1 on /media/System Reserved type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096) $ ls -a . A2B24EACB24E852F Ubuntu 12.04.1 LTS amd64 .. Elements System Reserved $ cat /proc/mounts rootfs / rootfs rw 0 0 sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 udev /dev devtmpfs rw,relatime,size=2013000k,nr_inodes=503250,mode=755 0 0 devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 tmpfs /run tmpfs rw,nosuid,relatime,size=809872k,mode=755 0 0 /dev/disk/by-uuid/77039a2a-83d4-47a1-8a8c-a2ec4e4dfd0e / ext4 rw,relatime,user_xattr,acl,barrier=1,data=ordered 0 0 none /sys/fs/fuse/connections fusectl rw,relatime 0 0 none /sys/kernel/debug debugfs rw,relatime 0 0 none /sys/kernel/security securityfs rw,relatime 0 0 none /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0 none /run/shm tmpfs rw,nosuid,nodev,relatime 0 0 /dev/sda1 /media/Elements fuseblk rw,nosuid,nodev,noexec,relatime,user_id=0,group_id=0,allow_other,blksize=4096 0 0 binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,nosuid,nodev,noexec,relatime 0 0 /home/solderblob/.Private /home/solderblob ecryptfs rw,relatime,ecryptfs_fnek_sig=391b2d8b155215f7,ecryptfs_sig=76a47b0175afa48d,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs 0 0 gvfs-fuse-daemon /home/solderblob/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0 /dev/sdb2 /media/A2B24EACB24E852F fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0 /dev/sdb1 /media/System\040Reserved fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0 gvfs-fuse-daemon /root/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0 $ fsck fsck from util-linux 2.20.1 e2fsck 1.42 (29-Nov-2011) /dev/sdb6 is mounted. WARNING!!! The filesystem is mounted. If you continue you ***WILL*** cause ***SEVERE*** filesystem damage. Do you really want to continue<n>? no check aborted.

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• No root file system is defined error after installation

  - by LearnCode

  I installed ubuntu through Wubi and once i rebooted I get no root file system defined error. here's the output of the boot_info_script.Could anyone point me out where the error is. Boot Info Script 0.60 from 17 May 2011 ============================= Boot Info Summary: =============================== => Windows is installed in the MBR of /dev/sda. => Windows is installed in the MBR of /dev/sdb. sda1: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7 Boot sector info: No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files: /bootmgr /Boot/BCD /Windows/System32/winload.exe /ntldr /ntdetect.com /wubildr /ubuntu/winboot/wubildr /wubildr.mbr /ubuntu/winboot/wubildr.mbr /ubuntu/disks/root.disk /ubuntu/disks/swap.disk sda1/Wubi: _____________________________________________________________________ File system: Boot sector type: Unknown Boot sector info: Mounting failed: mount: unknown filesystem type '' sda2: __________________________________________________________________________ File system: vfat Boot sector type: Unknown Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: /boot.ini /ntldr /NTDETECT.COM sdb1: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7 Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: ============================ Drive/Partition Info: ============================= Drive: sda _____________________________________________________________________ Disk /dev/sda: 160.0 GB, 160041885696 bytes 240 heads, 63 sectors/track, 20673 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sda1 * 63 301,250,879 301,250,817 7 NTFS / exFAT / HPFS /dev/sda2 301,250,943 312,575,759 11,324,817 c W95 FAT32 (LBA) GUID Partition Table detected, but does not seem to be used. Partition Start Sector End Sector # of Sectors System /dev/sda1 323,465,741,313,502,988275,962,973,585-323,465,465,350,529,402 - /dev/sda2 242,728,591,638,290,720578,721,383,108,845,578335,992,791,470,554,859 - /dev/sda3 1,827,498,311,425,204,2562,091,935,274,843,009,907264,436,963,417,805,652 - /dev/sda4 579,711,218,081,401,3572,006,665,459,744,645,1521,426,954,241,663,243,796 - /dev/sda11 270,286,346,402,038,1183,786,543,326,404,525,9543,516,256,980,002,487,837 - /dev/sda12 4,179,681,002,230,769,6684,179,389,374,010,033,387-291,628,220,736,280 - /dev/sda13 232,556,480,979,456,1311,160,152,593,793,119,235927,596,112,813,663,105 - /dev/sda14 98,342,784,050,266,9183,691,264,578,843,725,1953,592,921,794,793,458,278 - /dev/sda15 2,307,845,219,957,882,4961,850,841,032,955,276,350-457,004,187,002,606,145 - /dev/sda16 512,592,046,878,946,497368,458,231,024,779,444-144,133,815,854,167,052 - /dev/sda17 2,504,135,232,870,384,3923,665,087,872,719,320,8291,160,952,639,848,936,438 - /dev/sda18 3,783,181,605,270,691,304122,034,509,624,708,942-3,661,147,095,645,982,361 - /dev/sda19 3,519,661,520,275,829,5122,376,243,094,723,723,587-1,143,418,425,552,105,924 - /dev/sda20 3,867,920,076,859,0744,494,691,111,933,625,1044,490,823,191,856,766,031 - /dev/sda21 1,500,144,061,909,253,7612,511,182,033,846,676,3401,011,037,971,937,422,580 - /dev/sda22 13,035,625,499,900,0062,360,168,613,941,394,9472,347,132,988,441,494,942 - /dev/sda23 4,228,978,682,068,599,48813,159,423,631,648,263-4,215,819,258,436,951,224 - /dev/sda24 3,695,955,742,872,046,9084,561,928,726,501,845,776865,972,983,629,798,869 - /dev/sda25 1,297,460,286,683,948,0461,444,350,486,339,417,957146,890,199,655,469,912 - /dev/sda26 1,228,858,248,533,131,831 0-1,228,858,248,533,131,830 - /dev/sda121 3,189,184,846,146,487,1461,849,820,258,006,914,852-1,339,364,588,139,572,293 - /dev/sda122 1,226,215,547,991,800,578389,781,518,734,546,300-836,434,029,257,254,277 - /dev/sda123 3,851,660,168,574,583,4654,046,215,657,583,031,556194,555,489,008,448,092 - /dev/sda124 1,197,460,980,174,153,341699,103,965,005,093,246-498,357,015,169,060,094 - Drive: sdb _____________________________________________________________________ Disk /dev/sdb: 750.2 GB, 750153367552 bytes 255 heads, 63 sectors/track, 91200 cylinders, total 1465143296 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sdb1 2,048 1,465,143,295 1,465,141,248 7 NTFS / exFAT / HPFS "blkid" output: ________________________________________________________________ Device UUID TYPE LABEL /dev/loop0 iso9660 Ubuntu 11.04 amd64 /dev/loop1 squashfs /dev/sda1 E814B55B14B52E06 ntfs /dev/sda2 01CD-023B vfat HP_RECOVERY /dev/sdb1 7836F22A36F1E8D0 ntfs Elements ================================ Mount points: ================================= Device Mount_Point Type Options /dev/loop0 /cdrom iso9660 (ro,noatime) /dev/loop1 /rofs squashfs (ro,noatime) /dev/sdb1 /mnt fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) ================================ sda2/boot.ini: ================================ -------------------------------------------------------------------------------- [boot loader] timeout=0 default=C:\CMDCONS\BOOTSECT.DAT [operating systems] multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons -------------------------------------------------------------------------------- ======================== Unknown MBRs/Boot Sectors/etc: ======================== Unknown GPT Partiton Type c104043000e9b9040dff24b580010100 Unknown GPT Partiton Type 46313020746f20737461727420746865 Unknown GPT Partiton Type 65727920706172746974696f6e207761 Unknown GPT Partiton Type 727920706172746974696f6e0d0a0000 Unknown GPT Partiton Type 000f84e5f7668b162404e82804744066 Unknown GPT Partiton Type ce01e8dc038bfe66391624047505e8d9 Unknown GPT Partiton Type 0345086603f0e881030bd2740333d240 Unknown GPT Partiton Type bece01e8db0287fec645041266895508 Unknown GPT Partiton Type 01f60634010175078b363b01e854f5e8 Unknown GPT Partiton Type 313825740ffec03865107408fec03824 Unknown GPT Partiton Type 02f60634014074088bfdbece01e85101 Unknown GPT Partiton Type 263401f9e894f30f858ef4e8e201e8ec Unknown GPT Partiton Type f7e960f35245434f5645525966606633 Unknown GPT Partiton Type 660faf1e00106603dac3668b0e001066 Unknown GPT Partiton Type 8bfd386d04740583c710e2f6c36660c6 Unknown GPT Partiton Type 04ebf132c0b91000f3aac3bf0c04ebf3 Unknown GPT Partiton Type 02662bc1660fb71e0e02662bc366031e Unknown GPT Partiton Type f4b40ebb0700b901003c08751381ff25 Unknown GPT Partiton Type 534f465448494e4b90653f62011b0100 Unknown GPT Partiton Type 0b050900027777772e68702e636f6d00 Unknown GPT Partiton Type d441a0f5030003000ecb744a08bb3746 Unknown GPT Partiton Type f8579a116b4a7aa931cde97a4b9b5c09 Unknown GPT Partiton Type 7229990415b77c0a1970e7e824237a3a Unknown GPT Partiton Type afb6e34d6b4bd8c7c0eada19a9786cc3 Unknown BootLoader on sda1/Wubi 00000000 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 |0000000000000000| * 00000200 Unknown BootLoader on sda2 00000000 e9 a7 00 52 45 43 4f 56 45 52 59 00 02 08 20 00 |...RECOVERY... .| 00000010 02 00 00 00 00 f8 00 00 3f 00 f0 00 7f b9 f4 11 |........?.......| 00000020 8c cd ac 00 1e 2b 00 00 00 00 00 00 02 00 00 00 |.....+..........| 00000030 01 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000040 80 00 29 3b 02 cd 01 20 20 20 20 20 20 20 20 20 |..);... | 00000050 20 20 46 41 54 33 32 20 20 20 8b d0 c1 e2 02 80 | FAT32 ......| 00000060 e6 01 66 c1 e8 07 66 3b 46 f8 74 2a 66 89 46 f8 |..f...f;F.t*f.F.| 00000070 66 03 46 f4 66 0f b6 5e 28 80 e3 0f 74 0f 3a 5e |f.F.f..^(...t.:^| 00000080 10 0f 83 90 00 66 0f af 5e 24 66 03 c3 bb e0 07 |.....f..^$f.....| 00000090 b9 01 00 e8 cf 00 8b da 66 8b 87 00 7e 66 25 ff |........f...~f%.| 000000a0 ff ff 0f 66 3d f8 ff ff 0f c3 33 c9 8e d9 8e c1 |...f=.....3.....| 000000b0 8e d1 66 bc f4 7b 00 00 bd 00 7c 66 0f b6 46 10 |..f..{....|f..F.| 000000c0 66 f7 66 24 66 0f b7 56 0e 66 03 56 1c 66 89 56 |f.f$f..V.f.V.f.V| 000000d0 f4 66 03 c2 66 89 46 fc 66 c7 46 f8 ff ff ff ff |.f..f.F.f.F.....| 000000e0 66 8b 46 2c 66 50 e8 af 00 bb 70 00 b9 01 00 e8 |f.F,fP....p.....| 000000f0 73 00 bf 00 07 b1 0b be a9 7d f3 a6 74 2a 03 f9 |s........}..t*..| 00000100 83 c7 15 81 ff 00 09 72 ec 66 40 4a 75 db 66 58 |[email protected]| 00000110 e8 47 ff 72 cf be b4 7d ac 84 c0 74 09 b4 0e bb |.G.r...}...t....| 00000120 07 00 cd 10 eb f2 cd 19 66 58 ff 75 09 ff 75 0f |........fX.u..u.| 00000130 66 58 bb 00 20 66 83 f8 02 72 da 66 3d f8 ff ff |fX.. f...r.f=...| 00000140 0f 73 d2 66 50 e8 50 00 0f b6 4e 0d e8 16 00 c1 |.s.fP.P...N.....| 00000150 e1 05 03 d9 66 58 53 e8 00 ff 5b 72 d8 8a 56 40 |....fXS...[r..V@| 00000160 ea 00 00 00 20 66 60 66 6a 00 66 50 53 6a 00 66 |.... f`fj.fPSj.f| 00000170 68 10 00 01 00 8b f4 b8 00 42 8a 56 40 cd 13 be |h........B.V@...| 00000180 c7 7d 72 94 67 83 44 24 06 20 66 67 ff 44 24 08 |.}r.g.D$. fg.D$.| 00000190 e2 e3 83 c4 10 66 61 c3 66 48 66 48 66 0f b6 56 |.....fa.fHfHf..V| 000001a0 0d 66 f7 e2 66 03 46 fc c3 4e 54 4c 44 52 20 20 |.f..f.F..NTLDR | 000001b0 20 20 20 20 0d 0a 4e 6f 20 53 79 73 74 65 6d 20 | ..No System | 000001c0 44 69 73 6b 20 6f 72 0d 0a 44 69 73 6b 20 49 2f |Disk or..Disk I/| 000001d0 4f 20 65 72 72 6f 72 0d 0a 50 72 65 73 73 20 61 |O error..Press a| 000001e0 20 6b 65 79 20 74 6f 20 72 65 73 74 61 72 74 0d | key to restart.| 000001f0 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 =============================== StdErr Messages: =============================== umount: /isodevice: device is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1))

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• Oracle Flashback Technologies - Overview

  - by Sridhar_R-Oracle

  Oracle Flashback Technologies - IntroductionIn his May 29th 2014 blog, my colleague Joe Meeks introduced Oracle Maximum Availability Architecture (MAA) and discussed both planned and unplanned outages. Let’s take a closer look at unplanned outages. These can be caused by physical failures (e.g., server, storage, network, file deletion, physical corruption, site failures) or by logical failures – cases where all components and files are physically available, but data is incorrect or corrupt. These logical failures are usually caused by human errors or application logic errors. This blog series focuses on these logical errors – what causes them and how to address and recover from them using Oracle Database Flashback. In this introductory blog post, I’ll provide an overview of the Oracle Database Flashback technologies and will discuss the features in detail in future blog posts. Let’s get started. We are all human beings (unless a machine is reading this), and making mistakes is a part of what we do…often what we do best!  We “fat finger”, we spill drinks on keyboards, unplug the wrong cables, etc.  In addition, many of us, in our lives as DBAs or developers, must have observed, caused, or corrected one or more of the following unpleasant events: Accidentally updated a table with wrong values !! Performed a batch update that went wrong - due to logical errors in the code !! Dropped a table !! How do DBAs typically recover from these types of errors? First, data needs to be restored and recovered to the point-in-time when the error occurred (incomplete or point-in-time recovery).  Moreover, depending on the type of fault, it’s possible that some services – or even the entire database – would have to be taken down during the recovery process.Apart from error conditions, there are other questions that need to be addressed as part of the investigation. For example, what did the data look like in the morning, prior to the error? What were the various changes to the row(s) between two timestamps? Who performed the transaction and how can it be reversed?  Oracle Database includes built-in Flashback technologies, with features that address these challenges and questions, and enable you to perform faster, easier, and convenient recovery from logical corruptions. HistoryFlashback Query, the first Flashback Technology, was introduced in Oracle 9i. It provides a simple, powerful and completely non-disruptive mechanism for data verification and recovery from logical errors, and enables users to view the state of data at a previous point in time.Flashback Technologies were further enhanced in Oracle 10g, to provide fast, easy recovery at the database, table, row, and even at a transaction level.Oracle Database 11g introduced an innovative method to manage and query long-term historical data with Flashback Data Archive. The 11g release also introduced Flashback Transaction, which provides an easy, one-step operation to back out a transaction. Oracle Database versions 11.2.0.2 and beyond further enhanced the performance of these features. Note that all the features listed here work without requiring any kind of restore operation.In addition, Flashback features are fully supported with the new multi-tenant capabilities introduced with Oracle Database 12c, Flashback Features Oracle Flashback Database enables point-in-time-recovery of the entire database without requiring a traditional restore and recovery operation. It rewinds the entire database to a specified point in time in the past by undoing all the changes that were made since that time.Oracle Flashback Table enables an entire table or a set of tables to be recovered to a point in time in the past.Oracle Flashback Drop enables accidentally dropped tables and all dependent objects to be restored.Oracle Flashback Query enables data to be viewed at a point-in-time in the past. This feature can be used to view and reconstruct data that was lost due to unintentional change(s) or deletion(s). This feature can also be used to build self-service error correction into applications, empowering end-users to undo and correct their errors.Oracle Flashback Version Query offers the ability to query the historical changes to data between two points in time or system change numbers (SCN) Oracle Flashback Transaction Query enables changes to be examined at the transaction level. This capability can be used to diagnose problems, perform analysis, audit transactions, and even revert the transaction by undoing SQLOracle Flashback Transaction is a procedure used to back-out a transaction and its dependent transactions.Flashback technologies eliminate the need for a traditional restore and recovery process to fix logical corruptions or make enquiries. Using these technologies, you can recover from the error in the same amount of time it took to generate the error. All the Flashback features can be accessed either via SQL command line (or) via Enterprise Manager.  Most of the Flashback technologies depend on the available UNDO to retrieve older data. The following table describes the various Flashback technologies: their purpose, dependencies and situations where each individual technology can be used.   Example Syntax Error investigation related:The purpose is to investigate what went wrong and what the values were at certain points in timeFlashback Queries  ( select .. as of SCN | Timestamp )   - Helps to see the value of a row/set of rows at a point in timeFlashback Version Queries  ( select .. versions between SCN | Timestamp and SCN | Timestamp)  - Helps determine how the value evolved between certain SCNs or between timestamps Flashback Transaction Queries (select .. XID=)   - Helps to understand how the transaction caused the changes.Error correction related:The purpose is to fix the error and correct the problems,Flashback Table  (flashback table .. to SCN | Timestamp)  - To rewind the table to a particular timestamp or SCN to reverse unwanted updates Flashback Drop (flashback table ..  to before drop )  - To undrop or undelete a table Flashback Database (flashback database to SCN  | Restore Point )  - This is the rewind button for Oracle databases. You can revert the entire database to a particular point in time. It is a fast way to perform a PITR (point-in-time recovery). Flashback Transaction (DBMS_FLASHBACK.TRANSACTION_BACKOUT(XID..))  - To reverse a transaction and its related transactions Advanced use cases Flashback technology is integrated into Oracle Recovery Manager (RMAN) and Oracle Data Guard. So, apart from the basic use cases mentioned above, the following use cases are addressed using Oracle Flashback. Block Media recovery by RMAN - to perform block level recovery Snapshot Standby - where the standby is temporarily converted to a read/write environment for testing, backup, or migration purposes Re-instate old primary in a Data Guard environment – this avoids the need to restore an old backup and perform a recovery to make it a new standby. Guaranteed Restore Points - to bring back the entire database to an older point-in-time in a guaranteed way. and so on..I hope this introductory overview helps you understand how Flashback features can be used to investigate and recover from logical errors.  As mentioned earlier, I will take a deeper-dive into to some of the critical Flashback features in my upcoming blogs and address common use cases.

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• SQL University: What and why of database refactoring

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Tools of the trade This is a second part of the series and in it we’ll take a look at what database refactoring is and why do it. Why refactor a database To know why refactor we first have to know what refactoring actually is. Code refactoring is a process where we change module internals in a way that does not change that module’s input/output behavior. For successful refactoring there is one crucial thing we absolutely must have: Tests. Automated unit tests are the only guarantee we have that we haven’t broken the input/output behavior before refactoring. If you haven’t go back ad read my post on the matter. Then start writing them. Next thing you need is a code module. Those are views, UDFs and stored procedures. By having direct table access we can kiss fast and sweet refactoring good bye. One more point to have a database abstraction layer. And no, ORM’s don’t fall into that category. But also know that refactoring is NOT adding new functionality to your code. Many have fallen into this trap. Don’t be one of them and resist the lure of the dark side. And it’s a strong lure. We developers in general love to add new stuff to our code, but hate fixing our own mistakes or changing existing code for no apparent reason. To be a good refactorer one needs discipline and focus. Now we know that refactoring is all about changing inner workings of existing code. This can be due to performance optimizations, changing internal code workflows or some other reason. This is a typical black box scenario to the outside world. If we upgrade the car engine it still has to drive on the road (preferably faster) and not fly (no matter how cool that would be). Also be aware that white box tests will break when we refactor. What to refactor in a database Refactoring databases doesn’t happen that often but when it does it can include a lot of stuff. Let us look at a few common cases. Adding or removing database schema objects Adding, removing or changing table columns in any way, adding constraints, keys, etc… All of these can be counted as internal changes not visible to the data consumer. But each of these carries a potential input/output behavior change. Dropping a column can result in views not working anymore or stored procedure logic crashing. Adding a unique constraint shows duplicated data that shouldn’t exist. Foreign keys break a truncate table command executed from an application that runs once a month. All these scenarios are very real and can happen. With the proper database abstraction layer fully covered with black box tests we can make sure something like that does not happen (hopefully at all). Changing physical structures Physical structures include heaps, indexes and partitions. We can pretty much add or remove those without changing the data returned by the database. But the performance can be affected. So here we use our performance tests. We do have them, right? Just by adding a single index we can achieve orders of magnitude performance improvement. Won’t that make users happy? But what if that index causes our write operations to crawl to a stop. again we have to test this. There are a lot of things to think about and have tests for. Without tests we can’t do successful refactoring! Fixing bad code We all have some bad code in our systems. We usually refer to that code as code smell as they violate good coding practices. Examples of such code smells are SQL injection, use of SELECT *, scalar UDFs or cursors, etc… Each of those is huge code smell and can result in major code changes. Take SELECT * from example. If we remove a column from a table the client using that SELECT * statement won’t have a clue about that until it runs. Then it will gracefully crash and burn. Not to mention the widely unknown SELECT * view refresh problem that Tomas LaRock (@SQLRockstar on Twitter) and Colin Stasiuk (@BenchmarkIT on Twitter) talk about in detail. Go read about it, it’s informative. Refactoring this includes replacing the * with column names and most likely change to application using the database. Breaking apart huge stored procedures Have you ever seen seen a stored procedure that was 2000 lines long? I have. It’s not pretty. It hurts the eyes and sucks the will to live the next 10 minutes. They are a maintenance nightmare and turn into things no one dares to touch. I’m willing to bet that 100% of time they don’t have a single test on them. Large stored procedures (and functions) are a clear sign that they contain business logic. General opinion on good database coding practices says that business logic has no business in the database. That’s the applications part. Refactoring such behemoths requires writing lots of edge case tests for the stored procedure input/output behavior and then start to refactor it. First we split the logic inside into smaller parts like new stored procedures and UDFs. Those then get called from the master stored procedure. Once we’ve successfully modularized the database code it’s best to transfer that logic into the applications consuming it. This only leaves the stored procedure with common data manipulation logic. Of course this isn’t always possible so having a plethora of performance and behavior unit tests is absolutely necessary to confirm we’ve actually improved the codebase in some way.   Refactoring is not a popular chore amongst developers or managers. The former don’t like fixing old code, the latter can’t see the financial benefit. Remember how we talked about being lousy at estimating future costs in the previous post? But there comes a time when it must be done. Hopefully I’ve given you some ideas how to get started. In the last post of the series we’ll take a look at the tools to use and an example of testing and refactoring.

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• NUMA-aware placement of communication variables

  - by Dave

  For classic NUMA-aware programming I'm typically most concerned about simple cold, capacity and compulsory misses and whether we can satisfy the miss by locally connected memory or whether we have to pull the line from its home node over the coherent interconnect -- we'd like to minimize channel contention and conserve interconnect bandwidth. That is, for this style of programming we're quite aware of where memory is homed relative to the threads that will be accessing it. Ideally, a page is collocated on the node with the thread that's expected to most frequently access the page, as simple misses on the page can be satisfied without resorting to transferring the line over the interconnect. The default "first touch" NUMA page placement policy tends to work reasonable well in this regard. When a virtual page is first accessed, the operating system will attempt to provision and map that virtual page to a physical page allocated from the node where the accessing thread is running. It's worth noting that the node-level memory interleaving granularity is usually a multiple of the page size, so we can say that a given page P resides on some node N. That is, the memory underlying a page resides on just one node. But when thinking about accesses to heavily-written communication variables we normally consider what caches the lines underlying such variables might be resident in, and in what states. We want to minimize coherence misses and cache probe activity and interconnect traffic in general. I don't usually give much thought to the location of the home NUMA node underlying such highly shared variables. On a SPARC T5440, for instance, which consists of 4 T2+ processors connected by a central coherence hub, the home node and placement of heavily accessed communication variables has very little impact on performance. The variables are frequently accessed so likely in M-state in some cache, and the location of the home node is of little consequence because a requester can use cache-to-cache transfers to get the line. Or at least that's what I thought. Recently, though, I was exploring a simple shared memory point-to-point communication model where a client writes a request into a request mailbox and then busy-waits on a response variable. It's a simple example of delegation based on message passing. The server polls the request mailbox, and having fetched a new request value, performs some operation and then writes a reply value into the response variable. As noted above, on a T5440 performance is insensitive to the placement of the communication variables -- the request and response mailbox words. But on a Sun/Oracle X4800 I noticed that was not the case and that NUMA placement of the communication variables was actually quite important. For background an X4800 system consists of 8 Intel X7560 Xeons . Each package (socket) has 8 cores with 2 contexts per core, so the system is 8x8x2. Each package is also a NUMA node and has locally attached memory. Every package has 3 point-to-point QPI links for cache coherence, and the system is configured with a twisted ladder "mobius" topology. The cache coherence fabric is glueless -- there's not central arbiter or coherence hub. The maximum distance between any two nodes is just 2 hops over the QPI links. For any given node, 3 other nodes are 1 hop distant and the remaining 4 nodes are 2 hops distant. Using a single request (client) thread and a single response (server) thread, a benchmark harness explored all permutations of NUMA placement for the two threads and the two communication variables, measuring the average round-trip-time and throughput rate between the client and server. In this benchmark the server simply acts as a simple transponder, writing the request value plus 1 back into the reply field, so there's no particular computation phase and we're only measuring communication overheads. In addition to varying the placement of communication variables over pairs of nodes, we also explored variations where both variables were placed on one page (and thus on one node) -- either on the same cache line or different cache lines -- while varying the node where the variables reside along with the placement of the threads. The key observation was that if the client and server threads were on different nodes, then the best placement of variables was to have the request variable (written by the client and read by the server) reside on the same node as the client thread, and to place the response variable (written by the server and read by the client) on the same node as the server. That is, if you have a variable that's to be written by one thread and read by another, it should be homed with the writer thread. For our simple client-server model that means using split request and response communication variables with unidirectional message flow on a given page. This can yield up to twice the throughput of less favorable placement strategies. Our X4800 uses the QPI 1.0 protocol with source-based snooping. Briefly, when node A needs to probe a cache line it fires off snoop requests to all the nodes in the system. Those recipients then forward their response not to the original requester, but to the home node H of the cache line. H waits for and collects the responses, adjudicates and resolves conflicts and ensures memory-model ordering, and then sends a definitive reply back to the original requester A. If some node B needed to transfer the line to A, it will do so by cache-to-cache transfer and let H know about the disposition of the cache line. A needs to wait for the authoritative response from H. So if a thread on node A wants to write a value to be read by a thread on node B, the latency is dependent on the distances between A, B, and H. We observe the best performance when the written-to variable is co-homed with the writer A. That is, we want H and A to be the same node, as the writer doesn't need the home to respond over the QPI link, as the writer and the home reside on the very same node. With architecturally informed placement of communication variables we eliminate at least one QPI hop from the critical path. Newer Intel processors use the QPI 1.1 coherence protocol with home-based snooping. As noted above, under source-snooping a requester broadcasts snoop requests to all nodes. Those nodes send their response to the home node of the location, which provides memory ordering, reconciles conflicts, etc., and then posts a definitive reply to the requester. In home-based snooping the snoop probe goes directly to the home node and are not broadcast. The home node can consult snoop filters -- if present -- and send out requests to retrieve the line if necessary. The 3rd party owner of the line, if any, can respond either to the home or the original requester (or even to both) according to the protocol policies. There are myriad variations that have been implemented, and unfortunately vendor terminology doesn't always agree between vendors or with the academic taxonomy papers. The key is that home-snooping enables the use of a snoop filter to reduce interconnect traffic. And while home-snooping might have a longer critical path (latency) than source-based snooping, it also may require fewer messages and less overall bandwidth. It'll be interesting to reprise these experiments on a platform with home-based snooping. While collecting data I also noticed that there are placement concerns even in the seemingly trivial case when both threads and both variables reside on a single node. Internally, the cores on each X7560 package are connected by an internal ring. (Actually there are multiple contra-rotating rings). And the last-level on-chip cache (LLC) is partitioned in banks or slices, which with each slice being associated with a core on the ring topology. A hardware hash function associates each physical address with a specific home bank. Thus we face distance and topology concerns even for intra-package communications, although the latencies are not nearly the magnitude we see inter-package. I've not seen such communication distance artifacts on the T2+, where the cache banks are connected to the cores via a high-speed crossbar instead of a ring -- communication latencies seem more regular.

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• When is a Seek not a Seek?

  - by Paul White

  The following script creates a single-column clustered table containing the integers from 1 to 1,000 inclusive. IF OBJECT_ID(N'tempdb..#Test', N'U') IS NOT NULL DROP TABLE #Test ; GO CREATE TABLE #Test ( id INTEGER PRIMARY KEY CLUSTERED ); ; INSERT #Test (id) SELECT V.number FROM master.dbo.spt_values AS V WHERE V.[type] = N'P' AND V.number BETWEEN 1 AND 1000 ; Let’s say we need to find the rows with values from 100 to 170, excluding any values that divide exactly by 10.  One way to write that query would be: SELECT T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; That query produces a pretty efficient-looking query plan: Knowing that the source column is defined as an INTEGER, we could also express the query this way: SELECT T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; We get a similar-looking plan: If you look closely, you might notice that the line connecting the two icons is a little thinner than before.  The first query is estimated to produce 61.9167 rows – very close to the 63 rows we know the query will return.  The second query presents a tougher challenge for SQL Server because it doesn’t know how to predict the selectivity of the modulo expression (T.id % 10 > 0).  Without that last line, the second query is estimated to produce 68.1667 rows – a slight overestimate.  Adding the opaque modulo expression results in SQL Server guessing at the selectivity.  As you may know, the selectivity guess for a greater-than operation is 30%, so the final estimate is 30% of 68.1667, which comes to 20.45 rows. The second difference is that the Clustered Index Seek is costed at 99% of the estimated total for the statement.  For some reason, the final SELECT operator is assigned a small cost of 0.0000484 units; I have absolutely no idea why this is so, or what it models.  Nevertheless, we can compare the total cost for both queries: the first one comes in at 0.0033501 units, and the second at 0.0034054.  The important point is that the second query is costed very slightly higher than the first, even though it is expected to produce many fewer rows (20.45 versus 61.9167). If you run the two queries, they produce exactly the same results, and both complete so quickly that it is impossible to measure CPU usage for a single execution.  We can, however, compare the I/O statistics for a single run by running the queries with STATISTICS IO ON: Table '#Test'. Scan count 63, logical reads 126, physical reads 0. Table '#Test'. Scan count 01, logical reads 002, physical reads 0. The query with the IN list uses 126 logical reads (and has a ‘scan count’ of 63), while the second query form completes with just 2 logical reads (and a ‘scan count’ of 1).  It is no coincidence that 126 = 63 * 2, by the way.  It is almost as if the first query is doing 63 seeks, compared to one for the second query. In fact, that is exactly what it is doing.  There is no indication of this in the graphical plan, or the tool-tip that appears when you hover your mouse over the Clustered Index Seek icon.  To see the 63 seek operations, you have click on the Seek icon and look in the Properties window (press F4, or right-click and choose from the menu): The Seek Predicates list shows a total of 63 seek operations – one for each of the values from the IN list contained in the first query.  I have expanded the first seek node to show the details; it is seeking down the clustered index to find the entry with the value 101.  Each of the other 62 nodes expands similarly, and the same information is contained (even more verbosely) in the XML form of the plan. Each of the 63 seek operations starts at the root of the clustered index B-tree and navigates down to the leaf page that contains the sought key value.  Our table is just large enough to need a separate root page, so each seek incurs 2 logical reads (one for the root, and one for the leaf).  We can see the index depth using the INDEXPROPERTY function, or by using the a DMV: SELECT S.index_type_desc, S.index_depth FROM sys.dm_db_index_physical_stats ( DB_ID(N'tempdb'), OBJECT_ID(N'tempdb..#Test', N'U'), 1, 1, DEFAULT ) AS S ; Let’s look now at the Properties window when the Clustered Index Seek from the second query is selected: There is just one seek operation, which starts at the root of the index and navigates the B-tree looking for the first key that matches the Start range condition (id >= 101).  It then continues to read records at the leaf level of the index (following links between leaf-level pages if necessary) until it finds a row that does not meet the End range condition (id <= 169).  Every row that meets the seek range condition is also tested against the Residual Predicate highlighted above (id % 10 > 0), and is only returned if it matches that as well. You will not be surprised that the single seek (with a range scan and residual predicate) is much more efficient than 63 singleton seeks.  It is not 63 times more efficient (as the logical reads comparison would suggest), but it is around three times faster.  Let’s run both query forms 10,000 times and measure the elapsed time: DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON; SET STATISTICS XML OFF; ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; GO DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; On my laptop, running SQL Server 2008 build 4272 (SP2 CU2), the IN form of the query takes around 830ms and the range query about 300ms.  The main point of this post is not performance, however – it is meant as an introduction to the next few parts in this mini-series that will continue to explore scans and seeks in detail. When is a seek not a seek?  When it is 63 seeks © Paul White 2011 email: [email protected] twitter: @SQL_kiwi

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• BizTalk: Internals: the Partner Direct Ports and the Orchestration Chains

  - by Leonid Ganeline

  Partner Direct Port is one of the BizTalk hidden gems. It opens simple ways to the several messaging patterns. This article based on the Kevin Lam’s blog article. The article is pretty detailed but it still leaves several unclear pieces. So I have created a sample and will show how it works from different perspectives. Requirements We should create an orchestration chain where the messages should be routed from the first stage to the second stage. The messages should not be modified. All messages has the same message type. Common artifacts Source code can be downloaded here. It is interesting but all orchestrations use only one port type. It is possible because all ports are one-way ports and use only one operation. I have added a B orchestration. It helps to test the sample, showing all test messages in channel. The Receive shape Filter is empty. A Receive Port (R_Shema1Direct) is a plain Direct Port. As you can see, a subscription expression of this direct port has only one part, the MessageType for our test schema: A Filer is empty but, as you know, a link from the Receive shape to the Port creates this MessageType expression. I use only one Physical Receive File port to send a message to all processes. Each orchestration outputs a Trace.WriteLine(“<Orchestration Name>”). Forward Binding This sample has three orchestrations: A_1, A_21 and A_22. A_1 is a sender, A_21 and A_22 are receivers. Here is a subscription of the A_1 orchestration: It has two parts A MessageType. The same was for the B orchestration. A ReceivePortID. There was no such parameter for the B orchestration. It was created because I have bound the orchestration port with Physical Receive File port. This binding means the PortID parameter is added to the subscription. How to set up the ports? All ports involved in the message exchange should be the same port type. It forces us to use the same operation and the same message type for the bound ports. This step as absolutely contra-intuitive. We have to choose a Partner Orchestration parameter for the sending orchestration, A_1. The first strange thing is it is not a partner orchestration we have to choose but an orchestration port. But the most strange thing is we have to choose exactly this orchestration and exactly this port.It is not a port from the partner, receive orchestrations, A_21 or A_22, but it is A_1 orchestration and S_SentFromA_1 port. Now we have to choose a Partner Orchestration parameter for the received orchestrations, A_21 and A_22. Nothing strange is here except a parameter name. We choose the port of the sender, A_1 orchestration and S_SentFromA_1 port. As you can see the Partner Orchestration parameter for the sender and receiver orchestrations is the same. Testing I dropped a test file in a file folder. There we go: A dropped file was received by B and by A_1 A_1 sent a message forward. A message was received by B, A_21, A_22 Let’s look at a context of a message sent by A_1 on the second step: A MessageType part. It is quite expected. A PartnerService, a ParnerPort, an Operation. All those parameters were set up in the Partner Orchestration parameter on both bound ports.     Now let’s see a subscription of the A_21 and A_22 orchestrations. Now it makes sense. That’s why we have chosen such a strange value for the Partner Orchestration parameter of the sending orchestration. Inverse Binding This sample has three orchestrations: A_11, A_12 and A_2. A_11 and A_12 are senders, A_2 is receiver. How to set up the ports? All ports involved in the message exchange should be the same port type. It forces us to use the same operation and the same message type for the bound ports. This step as absolutely contra-intuitive. We have to choose a Partner Orchestration parameter for a receiving orchestration, A_2. The first strange thing is it is not a partner orchestration we have to choose but an orchestration port. But the most strange thing is we have to choose exactly this orchestration and exactly this port.It is not a port from the partner, sent orchestrations, A_11 or A_12, but it is A_2 orchestration and R_SentToA_2 port. Now we have to choose a Partner Orchestration parameter for the sending orchestrations, A_11 and A_12. Nothing strange is here except a parameter name. We choose the port of the sender, A_2 orchestration and R_SentToA_2 port. Testing I dropped a test file in a file folder. There we go: A dropped file was received by B, A_11 and by A_12 A_11 and A_12 sent two messages forward. The messages were received by B, A_2 Let’s see what was a context of a message sent by A_1 on the second step: A MessageType part. It is quite expected. A PartnerService, a ParnerPort, an Operation. All those parameters were set up in the Partner Orchestration parameter on both bound ports. Here is a subscription of the A_2 orchestration. Models I had a hard time trying to explain the Partner Direct Ports in simple terms. I have finished with this model: Forward Binding Receivers know a Sender. Sender doesn’t know Receivers. Publishers know a Subscriber. Subscriber doesn’t know Publishers. 1 –> 1 1 –> M Inverse Binding Senders know a Receiver. Receiver doesn’t know Senders. Subscribers know a Publisher. Publisher doesn’t know Subscribers. 1 –> 1 M –> 1 Notes   Orchestration chain It’s worth to note, the Partner Direct Port Binding creates a chain opened from one side and closed from another. The Forward Binding: A new Receiver can be added at run-time. The Sender can not be changed without design-time changes in Receivers. The Inverse Binding: A new Sender can be added at run-time. The Receiver can not be changed without design-time changes in Senders.

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• Oracle Certification and virtualization Solutions.

  - by scoter

  As stated in official MOS ( My Oracle Support ) document 249212.1 support for Oracle products on non-Oracle VM platforms follow exactly the same stance as support for VMware and, so, the only x86 virtualization software solution certified for any Oracle product is "Oracle VM". Based on the fact that: Oracle VM is totally free ( you have the option to buy Oracle-Support ) Certified is pretty different from supported ( OracleVM is certified, others could be supported ) With Oracle VM you may not require to reproduce your issue(s) on physical server Oracle VM is the only x86 software solution that allows hard-partitioning *** *** see details to these Oracle public links: http://www.oracle.com/technetwork/server-storage/vm/ovm-hardpart-168217.pdf http://www.oracle.com/us/corporate/pricing/partitioning-070609.pdf people started asking to migrate from third party virtualization software (ex. RH KVM, VMWare) to Oracle VM. Migrating RH KVM guest to Oracle VM. OracleVM has a built-in P2V utility ( Official Documentation ) but in some cases we can't use it, due to : network inaccessibility between hypervisors ( KVM and OVM ) network slowness between hypervisors (KVM and OVM) size of the guest virtual-disks Here you'll find a step-by-step guide to "manually" migrate a guest machine from KVM to OVM. 1. Verify source guest characteristics. Using KVM web console you can verify characteristics of the guest you need to migrate, such as: CPU Cores details Defined Memory ( RAM ) Name of your guest Guest operating system Disks details ( number and size ) Network details ( number of NICs and network configuration ) 2. Export your guest in OVF / OVA format.  The export from Redhat KVM ( kernel virtual machine ) will create a structured export of your guest: [root@ovmserver1 mnt]# lltotal 12drwxrwx--- 5 36 36 4096 Oct 19 2012 b8296fca-13c4-4841-a50f-773b5139fcee b8296fca-13c4-4841-a50f-773b5139fcee is the ID of the guest exported from RH-KVM [root@ovmserver1 mnt]# cd b8296fca-13c4-4841-a50f-773b5139fcee/[root@ovmserver1 b8296fca-13c4-4841-a50f-773b5139fcee]# ls -ltrtotal 12drwxr-x--- 4 36 36 4096 Oct 19  2012 masterdrwxrwx--- 2 36 36 4096 Oct 29  2012 dom_mddrwxrwx--- 4 36 36 4096 Oct 31  2012 images images contains your virtual-disks exported [root@ovmserver1 b8296fca-13c4-4841-a50f-773b5139fcee]# cd images/[root@ovmserver1 images]# ls -ltratotal 16drwxrwx--- 5 36 36 4096 Oct 19  2012 ..drwxrwx--- 2 36 36 4096 Oct 31  2012 d4ef928d-6dc6-4743-b20d-568b424728a5drwxrwx--- 2 36 36 4096 Oct 31  2012 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1drwxrwx--- 4 36 36 4096 Oct 31  2012 .[root@ovmserver1 images]# cd d4ef928d-6dc6-4743-b20d-568b424728a5/[root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# ls -ltotal 5169092-rwxr----- 1 36 36 187904819200 Oct 31  2012 4c03b1cf-67cc-4af0-ad1e-529fd665dac1-rw-rw---- 1 36 36          341 Oct 31  2012 4c03b1cf-67cc-4af0-ad1e-529fd665dac1.meta[root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# file 4c03b1cf-67cc-4af0-ad1e-529fd665dac14c03b1cf-67cc-4af0-ad1e-529fd665dac1: LVM2 (Linux Logical Volume Manager) , UUID: sZL1Ttpy0vNqykaPahEo3hK3lGhwspv 4c03b1cf-67cc-4af0-ad1e-529fd665dac1 is the first exported disk ( physical volume ) [root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# cd ../4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/[root@ovmserver1 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1]# ls -ltotal 5568076-rwxr----- 1 36 36 107374182400 Oct 31  2012 9020f2e1-7b8a-4641-8f80-749768cc237a-rw-rw---- 1 36 36          341 Oct 31  2012 9020f2e1-7b8a-4641-8f80-749768cc237a.meta[root@ovmserver1 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1]# file 9020f2e1-7b8a-4641-8f80-749768cc237a9020f2e1-7b8a-4641-8f80-749768cc237a: x86 boot sector; partition 1: ID=0x83, active, starthead 1, startsector 63, 401562 sectors; partition 2: ID=0x82, starthead 0, startsector 401625, 65529135 sectors; startsector 63, 401562 sectors; partition 2: ID=0x82, starthead 0, startsector 401625, 65529135 sectors; partition 3: ID=0x83, starthead 254, startsector 65930760, 8385930 sectors; partition 4: ID=0x5, starthead 254, startsector 74316690, 135395820 sectors, code offset 0x48 9020f2e1-7b8a-4641-8f80-749768cc237a is the second exported disk, with partition 1 bootable 3. Prepare the new guest on Oracle VM. By Ovm-Manager we can prepare the guest where we will move the exported virtual-disks; under the Tab "Servers and VMs": click on  and create your guest with parameters collected before (point 1): - add NICs on different networks: - add virtual-disks; in this case we add two disks of 1.0 GB each one; we will extend the virtual disk copying the source KVM virtual-disk ( see next steps ) - verify virtual-disks created ( under Repositories tab ) 4. Verify OVM virtual-disks names. [root@ovmserver1 VirtualMachines]# grep -r hyptest_rdbms * 0004fb0000060000a906b423f44da98e/vm.cfg:OVM_simple_name = 'hyptest_rdbms' [root@ovmserver1 VirtualMachines]# cd 0004fb0000060000a906b423f44da98e [root@ovmserver1 0004fb0000060000a906b423f44da98e]# more vm.cfgvif = ['mac=00:21:f6:0f:3f:85,bridge=0004fb001089128', 'mac=00:21:f6:0f:3f:8e,bridge=0004fb00101971d'] OVM_simple_name = 'hyptest_rdbms' vnclisten = '127.0.0.1' disk = ['file:/OVS/Repositories/0004fb00000300004f17b7368139eb41/ VirtualDisks/0004fb000012000097c1bfea9834b17d.img,xvda,w', 'file:/OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img,xvdb,w'] vncunused = '1' uuid = '0004fb00-0006-0000-a906-b423f44da98e' on_reboot = 'restart' cpu_weight = 27500 memory = 32768 cpu_cap = 0 maxvcpus = 8 OVM_high_availability = True maxmem = 32768 vnc = '1' OVM_description = '' on_poweroff = 'destroy' on_crash = 'restart' name = '0004fb0000060000a906b423f44da98e' guest_os_type = 'linux' builder = 'hvm' vcpus = 8 keymap = 'en-us' OVM_os_type = 'Oracle Linux 5' OVM_cpu_compat_group = '' OVM_domain_type = 'xen_hvm' disk2 ovm ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img disk1 ovm ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb000012000097c1bfea9834b17d.img Summarizing disk1 --source ==> /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/9020f2e1-7b8a-4641-8f80-749768cc237a disk1 --dest ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb000012000097c1bfea9834b17d.img disk2 --source ==> /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/d4ef928d-6dc6-4743-b20d-568b424728a5/4c03b1cf-67cc-4af0-ad1e-529fd665dac1 disk2 --dest ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img 5. Copy KVM exported virtual-disks to OVM virtual-disks. Keeping your Oracle VM guest stopped you can copy KVM exported virtual-disks to OVM virtual-disks; what I did is only to locally mount the filesystem containing the exported virtual-disk ( by an usb device ) on my OVS; the copy automatically resize OVM virtual-disks ( previously created with a size of 1GB ) . nohup cp /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/9020f2e1-7b8a-4641-8f80-749768cc237a /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/0004fb000012000097c1bfea9834b17d.img & nohup cp /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/d4ef928d-6dc6-4743-b20d-568b424728a5/4c03b1cf-67cc-4af0-ad1e-529fd665dac1 /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/0004fb0000120000cde6a11c3cb1d0be.img & 7. When copy completed refresh repository to aknowledge the new-disks size. 7. After "refresh repository" is completed, start guest machine by Oracle VM manager. After the first start of your guest: - verify that you can see all disks and partitions - verify that your guest is network reachable ( MAC Address of your NICs changed ) Eventually you can also evaluate to convert your guest to PVM ( Paravirtualized virtual Machine ) following official Oracle documentation. Ciao Simon COTER ps: next-time I'd like to post an article reporting how to manually migrate Virtual-Iron guests to OracleVM.  Comments and corrections are welcome. 

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• Different Not Automatically Implies Better

  - by Alois Kraus

  Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/11/05/154556.aspxRecently I was digging deeper why some WCF hosted workflow application did consume quite a lot of memory although it did basically only load a xaml workflow. The first tool of choice is Process Explorer or even better Process Hacker (has more options and the best feature copy&paste does work). The three most important numbers of a process with regards to memory are Working Set, Private Working Set and Private Bytes. Working set is the currently consumed physical memory (parts can be shared between processes e.g. loaded dlls which are read only) Private Working Set is the physical memory needed by this process which is not shareable Private Bytes is the number of non shareable which is only visible in the current process (e.g. all new, malloc, VirtualAlloc calls do create private bytes) When you have a bigger workflow it can consume under 64 bit easily 500MB for a 1-2 MB xaml file. This does not look very scalable. Under 64 bit the issue is excessive private bytes consumption and not the managed heap. The picture is quite different for 32 bit which looks a bit strange but it seems that the hosted VB compiler is a lot less memory hungry under 32 bit. I did try to repro the issue with a medium sized xaml file (400KB) which does contain 1000 variables and 1000 if which can be represented by C# code like this: string Var1; string Var2; ... string Var1000; if (!String.IsNullOrEmpty(Var1) ) { Console.WriteLine(“Var1”); } if (!String.IsNullOrEmpty(Var2) ) { Console.WriteLine(“Var2”); } ....   Since WF is based on VB.NET expressions you are bound to the hosted VB.NET compiler which does result in (x64) 140 MB of private bytes which is ca. 140 KB for each if clause which is quite a lot if you think about the actually present functionality. But there is hope. .NET 4.5 does allow now C# expressions for WF which is a major step forward for all C# lovers. I did create some simple patcher to “cross compile” my xaml to C# expressions. Lets look at the result: C# Expressions VB Expressions x86 x86 On my home machine I have only 32 bit which gives you quite exactly half of the memory consumption under 64 bit. C# expressions are 10 times more memory hungry than VB.NET expressions! I wanted to do more with less memory but instead it did consume a magnitude more memory. That is surprising to say the least. The workflow does initialize in about the same time under x64 and x86 where the VB code does it in 2s whereas the C# version needs 18s. Also nearly ten times slower. That is a too high price to pay for any bigger sized xaml workflow to convert from VB.NET to C# expressions. If I do reduce the number of expressions to 500 then it does need 400MB which is about half of the memory. It seems that the cost per if does rise linear with the number of total expressions in a xaml workflow.  Expression Language Cost per IF Startup Time C# 1000 Ifs x64 1,5 MB 18s C# 500 Ifs x64 750 KB 9s VB 1000 Ifs x64 140 KB 2s VB 500 Ifs x64 70 KB 1s Now we can directly compare two MS implementations. It is clear that the VB.NET compiler uses the same underlying structure but it has much higher offset compared to the highly inefficient C# expression compiler. I have filed a connect bug here with a harsher wording about recent advances in memory consumption. The funniest thing is that one MS employee did give an Azure AppFabric demo around early 2011 which was so slow that he needed to investigate with xperf. He was after startup time and the call stacks with regards to VB.NET expression compilation were remarkably similar. In fact I only found this post by googling for parts of my call stacks. … “C# expressions will be coming soon to WF, and that will have different performance characteristics than VB” … What did he know Jan 2011 what I did no know until today? ;-). He knew that C# expression will come but that they will not be automatically have better footprint. It is about time to fix that. In its current state C# expressions are not usable for bigger workflows. That also explains the headline for today. You can cheat startup time by prestarting workflows so that the demo looks nice and snappy but it does hurt scalability a lot since you do need much more memory than necessary. I did find the stacks by enabling virtual allocation tracking within XPerf which is still the best tool out there. But first you need to look at your process to check where the memory is hiding: For the C# Expression compiler you do not need xperf. You can directly dump the managed heap and check with a profiler of your choice. But if the allocations are happening on the Private Data ( VirtualAlloc ) you can find it with xperf. There is a nice video on channel 9 explaining VirtualAlloc tracking it in greater detail. If your data allocations are on the Heap it does mean that the C/C++ runtime did create a heap for you where all malloc, new calls do allocate from it. You can enable heap tracing with xperf and full call stack support as well which is doable via xperf like it is shown also on channel 9. Or you can use WPRUI directly: To make “Heap Usage” it work you need to set for your executable the tracing flags (before you start it). For example devenv.exe HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\devenv.exe DWORD TracingFlags 1 Do not forget to disable it after you did complete profiling the process or it will impact the startup time quite a lot. You can with xperf attach directly to a running process and collect heap allocation information from a gone wild process. Very handy if you need to find out what a process was doing which has arrived in a funny state. “VirtualAlloc usage” does work without explicitly enabling stuff for a specific process and is always on machine wide. I had issues on my Windows 7 machines with the call stack collection and the latest Windows 8.1 Performance Toolkit. I was told that WPA from Windows 8.0 should work fine but I do not want to downgrade.

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• Wired connection periodically disconnects requires ipconfig /release and /renew to reconnect

  - by Sesame

  I just got back into University and after a day of using the internet I suddenly was unable to visit other webpages even though I was still able to chat. I restarted the computer and the internet could no longer visit webpages at all. I got a DNS error from the browser (chrome) and the troubleshooter. The connection comes up as "Network 3" even though It was "Network 2" when it worked. I compared ipconfig /all logs and they seemed identical when it was and was not working. I've found two ways to get internet connection (they no longer work): run ipconfig /release and ipconfig /renew several times set a random address and have the troubleshooter fix the new found dhcp problem (before it says dns cannot fix). I checked and it said DHCP was enabled. But either step one or two usually needs to be repeated several times before the network will change back to "network 2" from the defunct "network 3" and after an hour or so I have problems again. I've tried: Uninstalling windows defender and turning off firewall (windows firewall). Updating Qualcomm Ethernet driver - it is up to date. System Restore (problem resurfaces quickly...it's possible this has something to do with windows update?) Flushing dns and setting dns myself (google one and others). Booting in safe mode with networking...didn't fix anything Reinstalling Ethernet Driver Using other ethernet cable, other wall port. I'm out of ideas. Ipconfig /all: Windows IP Configuration Host Name . . . . . . . . . . . . : NGoller Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : Home Ethernet adapter UConnect: Connection-specific DNS Suffix . : Home Description . . . . . . . . . . . : Qualcomm Atheros AR8151 PCI-E Gigabit Ethernet Controller Physical Address. . . . . . . . . : 90-2B-34-50-33-F4 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : fd00::2086:628:f0a1:73c3(Preferred) Temporary IPv6 Address. . . . . . : fd00::c86b:370:b1d9:bd73(Preferred) Link-local IPv6 Address . . . . . : fe80::2086:628:f0a1:73c3%11(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.0.33(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Wednesday, August 28, 2013 11:58:37 PM Lease Expires . . . . . . . . . . : Thursday, August 29, 2013 11:58:37 PM Default Gateway . . . . . . . . . : 192.168.0.1 DHCP Server . . . . . . . . . . . : 192.168.0.1 DNS Servers . . . . . . . . . . . : 192.168.0.1 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.Home: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Home Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Teredo Tunneling Pseudo-Interface: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes I'm getting these errors commonly: The IP address lease 155.97.227.199 for the Network Card with network address 0x902B345033F4 has been denied by the DHCP server 10.0.1.1 (The DHCP Server sent a DHCPNACK message). Event filter with query "SELECT * FROM __InstanceModificationEvent WITHIN 60 WHERE TargetInstance ISA "Win32_Processor" AND TargetInstance.LoadPercentage > 99" could not be reactivated in namespace "//./root/CIMV2" because of error 0x80041003. Events cannot be delivered through this filter until the problem is corrected. By the way, Operating System: Windows 7 - 64 Bit. Have downloaded latest windows updates. Update: And my two fixes don't work any more :( . This is now what happens when I try to Ipconfig /renew: C:\Users\Nikko\Desktop>ipconfig /renew Windows IP Configuration An error occurred while renewing interface Local Area Connection : The name spec ified in the network control block (NCB) is in use on a remote adapter. The NCB is the data. An error occurred while releasing interface Loopback Pseudo-Interface 1 : The sy stem cannot find the file specified. Update 2: So my internet is randomly working again today. The IP address I had before was a local one while the university address should start with 155... I didn't do anything to the settings...it's bizarre that it all of a sudden works. Thanks!

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• ndd on Solaris 10

  - by user12620111

  This is mostly a repost of LaoTsao's Weblog with some tweaks. Last time that I tried to cut & paste directly off of his page, some of the XML was messed up. I run this from my MacBook. It should also work from your windows laptop if you use cygwin. ================If not already present, create a ssh key on you laptop================ # ssh-keygen -t rsa ================ Enable passwordless ssh from my laptop. Need to type in the root password for the remote machines. Then, I no longer need to type in the password when I ssh or scp from my laptop to servers. ================ #!/usr/bin/env bash for server in `cat servers.txt` do   echo root@$server   cat ~/.ssh/id_rsa.pub | ssh root@$server "cat >> .ssh/authorized_keys" done ================ servers.txt ================ testhost1testhost2 ================ etc_system_addins ================ set rpcmod:clnt_max_conns=8 set zfs:zfs_arc_max=0x1000000000 set nfs:nfs3_bsize=131072 set nfs:nfs4_bsize=131072 ================ ndd-nettune.txt ================ #!/sbin/sh # # ident   "@(#)ndd-nettune.xml    1.0     01/08/06 SMI" . /lib/svc/share/smf_include.sh . /lib/svc/share/net_include.sh # Make sure that the libraries essential to this stage of booting  can be found. LD_LIBRARY_PATH=/lib; export LD_LIBRARY_PATH echo "Performing Directory Server Tuning..." >> /tmp/smf.out # # Standard SuperCluster Tunables # /usr/sbin/ndd -set /dev/tcp tcp_max_buf 2097152 /usr/sbin/ndd -set /dev/tcp tcp_xmit_hiwat 1048576 /usr/sbin/ndd -set /dev/tcp tcp_recv_hiwat 1048576 # Reset the library path now that we are past the critical stage unset LD_LIBRARY_PATH ================ ndd-nettune.xml ================ <?xml version="1.0"?> <!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1"> <!-- ident "@(#)ndd-nettune.xml 1.0 04/09/21 SMI" --> <service_bundle type='manifest' name='SUNWcsr:ndd'>   <service name='network/ndd-nettune' type='service' version='1'>     <create_default_instance enabled='true' />     <single_instance />     <dependency name='fs-minimal' type='service' grouping='require_all' restart_on='none'>       <service_fmri value='svc:/system/filesystem/minimal' />     </dependency>     <dependency name='loopback-network' grouping='require_any' restart_on='none' type='service'>       <service_fmri value='svc:/network/loopback' />     </dependency>     <dependency name='physical-network' grouping='optional_all' restart_on='none' type='service'>       <service_fmri value='svc:/network/physical' />     </dependency>     <exec_method type='method' name='start' exec='/lib/svc/method/ndd-nettune' timeout_seconds='3' > </exec_method>     <exec_method type='method' name='stop'  exec=':true'                       timeout_seconds='3' > </exec_method>     <property_group name='startd' type='framework'>       <propval name='duration' type='astring' value='transient' />     </property_group>     <stability value='Unstable' />     <template>       <common_name>     <loctext xml:lang='C'> ndd network tuning </loctext>       </common_name>       <documentation>     <manpage title='ndd' section='1M' manpath='/usr/share/man' />       </documentation>     </template>   </service> </service_bundle> ================ system_tuning.sh ================ #!/usr/bin/env bash for server in `cat servers.txt` do   cat etc_system_addins | ssh root@$server "cat >> /etc/system"   scp ndd-nettune.xml root@${server}:/var/svc/manifest/site/ndd-nettune.xml   scp ndd-nettune.txt root@${server}:/lib/svc/method/ndd-nettune   ssh root@$server chmod +x /lib/svc/method/ndd-nettune   ssh root@$server svccfg validate /var/svc/manifest/site/ndd-nettune.xml   ssh root@$server svccfg import /var/svc/manifest/site/ndd-nettune.xml done

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• Controlling the Sizing of the af:messages Dialog

  - by Duncan Mills

  Over the last day or so a small change in behaviour between 11.1.2.n releases of ADF and earlier versions has come to my attention. This has concerned the default sizing of the dialog that the framework automatically generates to handle the display of JSF messages being handled by the <af:messages> component. Unlike a normal popup, you don't have a physical <af:dialog> or <af:window> to set the sizing on in your page definition, so you're at the mercy of what the framework provides. In this case the framework now defines a fixed 250x250 pixel content area dialog for these messages, which can look a bit weird if the message is either very short, or very long. Unfortunately this is not something that you can control through the skin, instead you have to be a little more creative. Here's the solution I've come up with.  Unfortunately, I've not found a supportable way to reset the dialog so as to say  just size yourself based on your contents, it is actually possible to do this by tweaking the correct DOM objects, but I wanted to start with a mostly supportable solution that only uses the best practice of working through the ADF client side APIs. The Technique The basic approach I've taken is really very simple.  The af:messages dialog is just a normal richDialog object, it just happens to be one that is pre-defined for you with a particular known name "msgDlg" (which hopefully won't change). Knowing this, you can call the accepted APIs to control the content width and height of that dialog, as our meerkat friends would say, "simples" 1 The JavaScript For this example I've defined three JavaScript functions.   The first does all the hard work and is designed to be called from server side Java or from a page load event to set the default. The second is a utility function used by the first to validate the values you're about to use for height and width. The final function is one that can be called from the page load event to set an initial default sizing if that's all you need to do. Function resizeDefaultMessageDialog() /**  * Function that actually resets the default message dialog sizing.  * Note that the width and height supplied define the content area  * So the actual physical dialog size will be larger to account for  * the chrome containing the header / footer etc.  * @param docId Faces component id of the document  * @param contentWidth - new content width you need  * @param contentHeight - new content height  */ function resizeDefaultMessageDialog(docId, contentWidth, contentHeight) {   // Warning this value may change from release to release   var defMDName = "::msgDlg";   //Find the default messages dialog   msgDialogComponent = AdfPage.PAGE.findComponentByAbsoluteId(docId + defMDName); // In your version add a check here to ensure we've found the right object!   // Check the new width is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentWidth)){       msgDialogComponent.setContentWidth(contentWidth);   }   // Check the new height is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentHeight)){       msgDialogComponent.setContentHeight(contentHeight);   } }  Function dimensionIsValid()  /**  * Simple function to check that sensible numeric values are   * being proposed for a dimension  * @param sampleDimension   * @return booolean  */ function dimensionIsValid(sampleDimension){     return (!isNaN(sampleDimension) && sampleDimension > 0); } Function  initializeDefaultMessageDialogSize() /**  * This function will re-define the default sizing applied by the framework   * in 11.1.2.n versions  * It is designed to be called with the document onLoad event  */ function initializeDefaultMessageDialogSize(loadEvent){   //get the configuration information   var documentId = loadEvent.getSource().getProperty('documentId');   var newWidth = loadEvent.getSource().getProperty('defaultMessageDialogContentWidth');   var newHeight = loadEvent.getSource().getProperty('defaultMessageDialogContentHeight');   resizeDefaultMessageDialog(documentId, newWidth, newHeight); } Wiring in the Functions As usual, the first thing we need to do when using JavaScript with ADF is to define an af:resource  in the document metaContainer facet <af:document>   ....     <f:facet name="metaContainer">     <af:resource type="javascript" source="/resources/js/hackMessagedDialog.js"/>    </f:facet> </af:document> This makes the script functions available to call.  Next if you want to use the option of defining an initial default size for the dialog you use a combination of <af:clientListener> and <af:clientAttribute> tags like this. <af:document title="MyApp" id="doc1">   <af:clientListener method="initializeDefaultMessageDialogSize" type="load"/>   <af:clientAttribute name="documentId" value="doc1"/>   <af:clientAttribute name="defaultMessageDialogContentWidth" value="400"/>   <af:clientAttribute name="defaultMessageDialogContentHeight" value="150"/>  ...   Just in Time Dialog Sizing  So  what happens if you have a variety of messages that you might add and in some cases you need a small dialog and an other cases a large one? Well in that case you can re-size these dialogs just before you submit the message. Here's some example Java code: FacesContext ctx = FacesContext.getCurrentInstance();          //reset the default dialog size for this message ExtendedRenderKitService service =              Service.getRenderKitService(ctx, ExtendedRenderKitService.class); service.addScript(ctx, "resizeDefaultMessageDialog('doc1',100,50);");          FacesMessage msg = new FacesMessage("Short message"); msg.setSeverity(FacesMessage.SEVERITY_ERROR); ctx.addMessage(null, msg);  So there you have it. This technique should, at least, allow you to control the dialog sizing just enough to stop really objectionable whitespace or scrollbars. 1 Don't worry if you don't get the reference, lest's just say my kids watch too many adverts.

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• Data Modeling: Logical Modeling Exercise

  - by swisscheese

  In trying to learn the art of data storage I have been trying to take in as much solid information as possible. PerformanceDBA posted some really helpful tutorials/examples in the following posts among others: is my data normalized? and Relational table naming convention. I already asked a subset question of this model here. So to make sure I understood the concepts he presented and I have seen elsewhere I wanted to take things a step or two further and see if I am grasping the concepts. Hence the purpose of this post, which hopefully others can also learn from. Everything I present is conceptual to me and for learning rather than applying it in some production system. It would be cool to get some input from PerformanceDBA also since I used his models to get started, but I appreciate all input given from anyone. As I am new to databases and especially modeling I will be the first to admit that I may not always ask the right questions, explain my thoughts clearly, or use the right verbage due to lack of expertise on the subject. So please keep that in mind and feel free to steer me in the right direction if I head off track. If there is enough interest in this I would like to take this from the logical to physical phases to show the evolution of the process and share it here on Stack. I will keep this thread for the Logical Diagram though and start new one for the additional steps. For my understanding I will be building a MySQL DB in the end to run some tests and see if what I came up with actually works. Here is the list of things that I want to capture in this conceptual model. Edit for V1.2 The purpose of this is to list Bands, their members, and the Events that they will be appearing at, as well as offer music and other merchandise for sale Members will be able to match up with friends Members can write reviews on the Bands, their music, and their events. There can only be one review per member on a given item, although they can edit their reviews and history will be maintained. BandMembers will have the chance to write a single Comment on Reviews about the Band they are associated with. Collectively as a Band only one Comment is allowed per Review. Members can then rate all Reviews and Comments but only once per given instance Members can select their favorite Bands, music, Merchandise, and Events Bands, Songs, and Events will be categorized into the type of Genre that they are and then further subcategorized into a SubGenre if necessary. It is ok for a Band or Event to fall into more then one Genre/SubGenre combination. Event date, time, and location will be posted for a given band and members can show that they will be attending the Event. An Event can be comprised of more than one Band, and multiple Events can take place at a single location on the same day Every party will be tied to at least one address and address history shall be maintained. Each party could also be tied to more then one address at a time (i.e. billing, shipping, physical) There will be stored profiles for Bands, BandMembers, and general members. So there it is, maybe a bit involved but could be a great learning tool for many hopefully as the process evolves and input is given by the community. Any input? EDIT v1.1 In response to PerformanceDBA U.3) That means no merchandise other than Band merchandise in the database. Correct ? That was my original thought but you got me thinking. Maybe the site would want to sell its own merchandise or even other merchandise from the bands. Not sure a mod to make for that. Would it require an entire rework of the Catalog section or just the identifying relationship that exists with the Band? Attempted a mod to sell both complete albums or song. Either way they would both be in electronic format only available for download. That is why I listed an Album as being comprised of Songs rather then 2 separate entities. U.5) I understand what you bring up about the circular relation with Favorite. I would like to get to this “It is either one Entity with some form of differentiation (FavoriteType) which identifies its treatment” but how to is not clear to me. What am I missing here? u.6) “Business Rules This is probably the only area you are weak in.” Thanks for the honest response. I will readdress these but I hope to clear up some confusion in my head first with the responses I have posted back to you. Q.1) Yes I would like to have Accepted, Rejected, and Blocked. I am not sure what you are referring to as to how this would change the logical model? Q.2) A person does not have to be a User. They can exist only as a BandMember. Is that what you are asking? Minor Issue Zero, One, or More…Oops I admit I forgot to give this attention when building the model. I am submitting this version as is and will address in a future version. I need to read up more on Constraint Checking to make sure I am understanding things. M.4) Depends if you envision OrderPurchase in the future. Can you expand as to what you mean here? EDIT V1.2 In response to PerformanceDBA input... Lessons learned. I was mixing the concept of Identifying / Non-Identifying and Cardinality (i.e. Genre / SubGenre), and doing so inconsistently to make things worse. Associative Tables are not required in Logical Diagrams as their many-to-many relationships can be depicted and then expanded in the Physical Model. I was overlooking the Cardinality in a lot of the relationships The importance of reading through relationships using effective Verb Phrases to reassure I am modeling what I want to accomplish. U.2) In the concept of this model it is only required to track a Venue as a location for an Event. No further data needs to be collected. With that being said Events will take place on a given EventDate and will be hosted at a Venue. Venues will host multiple events and possibly multiple events on a given date. In my new model my thinking was that EventDate is already tied to Event . Therefore, Venue will not need a relationship with EventDate. The 5th and 6th bullets you have listed under U.2) leave me questioning my thinking though. Am I missing something here? U.3) Is it time to move the link between Item and Band up to Item and Party instead? With the current design I don't see a possibility to sell merchandise not tied to the band as you have brought up. U.5) I left as per your input rather than making it a discrete Supertype/Subtype Relationship as I don’t see a benefit of having that type of roll up. Additional Revisions AR.1) After going through the exercise for FavoriteItem, I feel that Item to Review requires a many-to-many relationship so that is indicated. Necessary? Ok here we go for v1.3 I took a few days on this version, going back and forth with my design. Once the logical process is complete, as I want to see if I am on the right track, I will go through in depth what I had learned and the troubles I faced as a beginner going through this process. The big point for this version was it took throwing in some Keys to help see what I was missing in the past. Going through the process of doing a matrix proved to be of great help also. Regardless of anything, if it wasn't for the input given by PerformanceDBA I would still be a lost soul wondering in the dark. Who knows my current design might reaffirm that I still am, but I have learned a lot so I am know I at least have a flashlight in my hand. At this point in time I admit that I am still confused about identifying and non-identifying relationships. In my model I had to use non-identifying relationships with non nulls just to join the relationships I wanted to model. In reading a lot on the subject there seems to be a lot of disagreement and indecisiveness on the subject so I did what I thought represented the right things in my model. When to force (identifying) and when to be free (non-identifying)? Anyone have inputs? EDIT V1.4 Ok took the V1.3 inputs and cleaned things up for this V1.4 Currently working on a V1.5 to include attributes.

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• HTTP Error 403.18 - Forbidden - asp.net mvc web api

  - by CoffeeCode

  I have deployed the default asp.net mvc 4 web api project to my windows server 2008 RC and am experiensing some issues with calling the web api actions. I'm quite new in the server/iis configuration part. I can open the home page, but the API part doesnt work. I'm getting such an error: HTTP Error 403.18 - Forbidden The specified request cannot be processed in the application pool that is configured for this resource on the Web server Module IIS Web Core Notification BeginRequest Handler StaticFile Error Code 0x00000000 Requested URL http://server.com:80/index.php?p=MvcApplication2_deploy/api/values/ Physical Path C:\Inetpub\vhosts\server.com\Webservice\index.php Logon Method Not yet determined Logon User Not yet determined I have checked Url Rewrite it is empty, have disabled WebDAV and also checked the Handler Mappings every thing seems to be ok there. Could any one give me some hints what could be wrong? Thanks!!!

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• Random Windows application crashes on Windows Server Hyper-V Core 2012

  - by Marlamin

  We're having some issues with our Hyper-V Core 2012 R2 installation on a HP DL360G8. We have an identical server with Hyper-V Core 2012 (not R2) that does not have these issues. When logging off from the physical server/via remote desktop, we sometimes get this error: Configure-SMRemoting.exe - Application Error : The application was unable to start correctly (0xc0000142). Click OK to close the application. We've also once or twice seen a "memory could not be read" error mentioning LoginUI.exe (another Windows app in System32) but have been unable to get an exact description. It's rather worrying to get such errors on a fresh install of Hyper-V 2012 R2. Is this even anything to worry about? Things we've done: Memtest86+, no memory errors Checksummed the file that is crashing with the one in the verified correct ISO, files match Server firmware upgrade to latest firmware of all present hardware, no visible changes Remade the RAID5 array , no change Reinstalled a few times, no change Reinstall without applying Windows updates after, no change

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• Make vmware virtual machine from HDD with bad sectros

  - by mike1616

  I have a notebook with a bad HDD (it has bad sectors). I would like make a virtual disk with VMware workstation from this computer. I installed VMware Workstation & VMware vCenter Converter Standalone Client on this notebook, then I used virtualize a physical machine. It started procedure but at 38% I got this error: FAILED: An error occurred during the conversion: 'BlockLevelVolumeCloneMgr::CloneVolume: Detected a write error during the cloning of volume \WindowsBitmapDriverVolumeId=[39-06-3A-06-00-02-13-4C-1D-00-00-00]. Error: 209 (type: 1, code: 13)' I Googled it and I think it means that I have bad sectors on the HDD. How can I solve this problem and make a virtual machine from HDD with bad sectors?

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