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• 13.10 - Weird WiFi connection problems - WMP300N - Broadcom BCM4321

  - by user1898041

  Just installed 13.10 on my desktop and I really like it. After having problems with getting the wifi to work, I installed it connected to the internet with an ethernet cable and added in the 3rd party software and updates as per the installation procedure. After installation was completed, I saw the wifi icon in the upper right hand corner, but it was not seeing any wifi networks. Some Googling brought me to use the 'Additional Drivers' application. It found the WMP300N Broadcom BDM4321 based pci wifi card and installed the proprietary Broadcom STA wireless driver, which may have been installed before. I'm not sure. Here is the weird part: when I start my system, wifi seems to be in some sort of suspended state where the system sees that the card exists but the card will not detect any wifi networks. It will work after booting once I 'Additional Drivers' application and then start FireFox. I know it seems weird, but this is the process I've got down to get the card to recognize wifi networks. After those applications are open for a few seconds, the card starts to function like normal (although maintaining the wifi connection is problem but most likely a seperate issue). The reason this is a problem is because this is supposed to just be a headless box managed through SSH. Here are the readouts from the common network diagnosis programs BEFORE I open 'Additional Drivers' and 'FireFox'. All commands were done with sudo. lspci 00:00.0 Host bridge: Intel Corporation 82G35 Express DRAM Controller (rev 03) 00:01.0 PCI bridge: Intel Corporation 82G35 Express PCI Express Root Port (rev 03) 00:1a.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 02) 00:1a.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 02) 00:1a.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 02) 00:1a.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 02) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) 00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 02) 00:1c.4 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 5 (rev 02) 00:1c.5 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 6 (rev 02) 00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 02) 00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 02) 00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02) 00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 02) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 92) 00:1f.0 ISA bridge: Intel Corporation 82801IR (ICH9R) LPC Interface Controller (rev 02) 00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] (rev 02) 00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02) 01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce GT 220] (rev a2) 01:00.1 Audio device: NVIDIA Corporation High Definition Audio Controller (rev a1) 02:00.0 Ethernet controller: Qualcomm Atheros Attansic L1 Gigabit Ethernet (rev b0) 03:00.0 IDE interface: JMicron Technology Corp. JMB368 IDE controller 05:00.0 Network controller: Broadcom Corporation BCM4321 802.11b/g/n (rev 01) 05:03.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6306/7/8 [Fire II(M)] IEEE 1394 OHCI Controller (rev c0) - lshw *-network description: Ethernet interface product: Attansic L1 Gigabit Ethernet vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: b0 serial: 00:22:15:00:a8:12 capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1 driverversion=2.1.3 latency=0 link=no multicast=yes port=twisted pair resources: irq:46 memory:feac0000-feafffff memory:feaa0000-feabffff *-network description: Wireless interface product: BCM4321 802.11b/g/n vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:05:00.0 logical name: eth1 version: 01 serial: 00:23:69:d8:2b:16 width: 32 bits clock: 33MHz capabilities: bus_master ethernet physical wireless configuration: broadcast=yes driver=wl0 driverversion=6.30.223.141 (r415941) latency=64 multicast=yes wireless=IEEE 802.11abg resources: irq:16 memory:febfc000-febfffff - ifconfig eth0 Link encap:Ethernet HWaddr 00:22:15:00:a8:12 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) eth1 Link encap:Ethernet HWaddr 00:23:69:d8:2b:16 inet6 addr: fe80::223:69ff:fed8:2b16/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:16 Base address:0xc000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:24 errors:0 dropped:0 overruns:0 frame:0 TX packets:24 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1856 (1.8 KB) TX bytes:1856 (1.8 KB) - iwconfig eth1 IEEE 802.11abg ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=200 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off - iwlist scan eth1 No scan results - Here are the various commands AFTER I open 'Additional Drivers' and 'FireFox' lspci 00:00.0 Host bridge: Intel Corporation 82G35 Express DRAM Controller (rev 03) 00:01.0 PCI bridge: Intel Corporation 82G35 Express PCI Express Root Port (rev 03) 00:1a.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 02) 00:1a.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 02) 00:1a.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 02) 00:1a.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 02) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) 00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 02) 00:1c.4 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 5 (rev 02) 00:1c.5 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 6 (rev 02) 00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 02) 00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 02) 00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 02) 00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 02) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 92) 00:1f.0 ISA bridge: Intel Corporation 82801IR (ICH9R) LPC Interface Controller (rev 02) 00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] (rev 02) 00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 02) 01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce GT 220] (rev a2) 01:00.1 Audio device: NVIDIA Corporation High Definition Audio Controller (rev a1) 02:00.0 Ethernet controller: Qualcomm Atheros Attansic L1 Gigabit Ethernet (rev b0) 03:00.0 IDE interface: JMicron Technology Corp. JMB368 IDE controller 05:00.0 Network controller: Broadcom Corporation BCM4321 802.11b/g/n (rev 01) 05:03.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6306/7/8 [Fire II(M)] IEEE 1394 OHCI Controller (rev c0) - lshw *-network description: Ethernet interface product: Attansic L1 Gigabit Ethernet vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: b0 serial: 00:22:15:00:a8:12 capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1 driverversion=2.1.3 latency=0 link=no multicast=yes port=twisted pair resources: irq:46 memory:feac0000-feafffff memory:feaa0000-feabffff *-network description: Wireless interface product: BCM4321 802.11b/g/n vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:05:00.0 logical name: eth1 version: 01 serial: 00:23:69:d8:2b:16 width: 32 bits clock: 33MHz capabilities: bus_master ethernet physical wireless configuration: broadcast=yes driver=wl0 driverversion=6.30.223.141 (r415941) ip=192.168.1.103 latency=64 multicast=yes wireless=IEEE 802.11abg resources: irq:16 memory:febfc000-febfffff - ifconfig eth0 Link encap:Ethernet HWaddr 00:22:15:00:a8:12 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) eth1 Link encap:Ethernet HWaddr 00:23:69:d8:2b:16 inet addr:192.168.1.103 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::223:69ff:fed8:2b16/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:85 errors:0 dropped:0 overruns:0 frame:11901 TX packets:132 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:52641 (52.6 KB) TX bytes:19058 (19.0 KB) Interrupt:16 Base address:0xc000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:76 errors:0 dropped:0 overruns:0 frame:0 TX packets:76 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:6084 (6.0 KB) TX bytes:6084 (6.0 KB) - iwconfig eth1 IEEE 802.11abg ESSID:"BU" Mode:Managed Frequency:2.447 GHz Access Point: 00:26:F2:1F:81:02 Bit Rate=54 Mb/s Tx-Power=200 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off Link Quality=59/70 Signal level=-51 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 - iwlist scan A LOT OF SSIDs FOUND! - I'd like to have this problem fixed, but I'm not quite sure where to go. Been Googling a lot and can't seem to find anyone else with this problem.

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• Identity in .NET 4.5&ndash;Part 2: Claims Transformation in ASP.NET (Beta 1)

  - by Your DisplayName here!

  In my last post I described how every identity in .NET 4.5 is now claims-based. If you are coming from WIF you might think, great – how do I transform those claims? Sidebar: What is claims transformation? One of the most essential features of WIF (and .NET 4.5) is the ability to transform credentials (or tokens) to claims. During that process the “low level” token details are turned into claims. An example would be a Windows token – it contains things like the name of the user and to which groups he belongs to. That information will be surfaced as claims of type Name and GroupSid. Forms users will be represented as a Name claim (all the other claims that WIF provided for FormsIdentity are gone in 4.5). The issue here is, that your applications typically don’t care about those low level details, but rather about “what’s the purchase limit of alice”. The process of turning the low level claims into application specific ones is called claims transformation. In pre-claims times this would have been done by a combination of Forms Authentication extensibility, role manager and maybe ASP.NET profile. With claims transformation all your identity gathering code is in one place (and the outcome can be cached in a single place as opposed to multiple ones). The structural class to do claims transformation is called ClaimsAuthenticationManager. This class has two purposes – first looking at the incoming (low level) principal and making sure all required information about the user is present. This is your first chance to reject a request. And second – modeling identity information in a way it is relevant for the application (see also here). This class gets called (when present) during the pipeline when using WS-Federation. But not when using the standard .NET principals. I am not sure why – maybe because it is beta 1. Anyhow, a number of people asked me about it, and the following is a little HTTP module that brings that feature back in 4.5. public class ClaimsTransformationHttpModule : IHttpModule {     public void Dispose()     { }     public void Init(HttpApplication context)     {         context.PostAuthenticateRequest += Context_PostAuthenticateRequest;     }     void Context_PostAuthenticateRequest(object sender, EventArgs e)     {         var context = ((HttpApplication)sender).Context;         // no need to call transformation if session already exists         if (FederatedAuthentication.SessionAuthenticationModule != null &&             FederatedAuthentication.SessionAuthenticationModule.ContainsSessionTokenCookie(context.Request.Cookies))         {             return;         }         var transformer = FederatedAuthentication.FederationConfiguration.IdentityConfiguration.ClaimsAuthenticationManager;         if (transformer != null)         {             var transformedPrincipal = transformer.Authenticate(context.Request.RawUrl, context.User as ClaimsPrincipal);             context.User = transformedPrincipal;             Thread.CurrentPrincipal = transformedPrincipal;         }     } } HTH

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• what can be causes of http server crash?

  - by mithunmo

  Hello , I am using WAMP server on Windows XP. - Apache 2.2.11 - MySQL 5.1.36 (INNODB engine) - PHP 5.3.0 I observe that my WAMP server crashes in the following scenarios 1) IF I use a Low end PC ( low processor speed and low RAM) 2) After making some changes to httpd.conf file .For eg changing the Allow from IP address . But here it crashes only once and then it starts to work fine. 3) Random crashes CRASH LOG szAppName : httpd.exe szAppVer : 2.2.11.0 szModName : php5ts.dll szModVer : 5.3.0.0 offset : 0000c309 C:\DOCUME~1\blrcom\LOCALS~1\Temp\WERc677.dir00\httpd.exe.mdmp C:\DOCUME~1\blrcom\LOCALS~1\Temp\WERc677.dir00\appcompat.txt My questions 1) Does high CPU utilization/LOW RAM can also cause the HTTP server to crash ? 2) excessive file reading as in every 10 seconds ? 3) unlimited script execution time . I have set the maximum execution time in php script to 0 as my script has to execute for sometimes 2-3 days. Is there any way to avoid this ? 4) Access to Database ? Should we use lock before reading and writing Can these be the reasons for random wamp server crashes ? OR is is some other programming error ? Please guide me . Regards, Mithun

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• Average performance of binary search algorithm?

  - by Passionate Learner

  http://en.wikipedia.org/wiki/Binary_search_algorithm#Average_performance BinarySearch(int A[], int value, int low, int high) { int mid; if (high < low) return -1; mid = (low + high) / 2; if (A[mid] > value) return BinarySearch(A, value, low, mid-1); else if (A[mid] < value) return BinarySearch(A, value, mid+1, high); else return mid; } If the integer I'm trying to find is always in the array, can anyone help me write a program that can calculate the average performance of binary search algorithm? I know I can do this by actually running the program and counting the number of calls, but what I'm trying to do here is to do it without calling the function. I'm not asking for a time complexity, I'm trying to calculate the average number of calls. For example, the average number of calls to find a integer in A[2], it would be 1.67 (5/3).

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• How to minimize total cost of shortest path tree

  - by Michael

  I have a directed acyclic graph with positive edge-weights. It has a single source and a set of targets (vertices furthest from the source). I find the shortest paths from the source to each target. Some of these paths overlap. What I want is a shortest path tree which minimizes the total sum of weights over all edges. For example, consider two of the targets. Given all edge weights equal, if they share a single shortest path for most of their length, then that is preferable to two mostly non-overlapping shortest paths (fewer edges in the tree equals lower overall cost). Another example: two paths are non-overlapping for a small part of their length, with high cost for the non-overlapping paths, but low cost for the long shared path (low combined cost). On the other hand, two paths are non-overlapping for most of their length, with low costs for the non-overlapping paths, but high cost for the short shared path (also, low combined cost). There are many combinations. I want to find solutions with the lowest overall cost, given all the shortest paths from source to target. Does this ring any bells with anyone? Can anyone point me to relevant algorithms or analogous applications? Cheers!

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• SQL SERVER – Shrinking Database is Bad – Increases Fragmentation – Reduces Performance

  - by pinaldave

  Earlier, I had written two articles related to Shrinking Database. I wrote about why Shrinking Database is not good. SQL SERVER – SHRINKDATABASE For Every Database in the SQL Server SQL SERVER – What the Business Says Is Not What the Business Wants I received many comments on Why Database Shrinking is bad. Today we will go over a very interesting example that I have created for the same. Here are the quick steps of the example. Create a test database Create two tables and populate with data Check the size of both the tables Size of database is very low Check the Fragmentation of one table Fragmentation will be very low Truncate another table Check the size of the table Check the fragmentation of the one table Fragmentation will be very low SHRINK Database Check the size of the table Check the fragmentation of the one table Fragmentation will be very HIGH REBUILD index on one table Check the size of the table Size of database is very HIGH Check the fragmentation of the one table Fragmentation will be very low Here is the script for the same. USE MASTER GO CREATE DATABASE ShrinkIsBed GO USE ShrinkIsBed GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Create FirstTable CREATE TABLE FirstTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Create Clustered Index on ID CREATE CLUSTERED INDEX [IX_FirstTable_ID] ON FirstTable ( [ID] ASC ) ON [PRIMARY] GO -- Create SecondTable CREATE TABLE SecondTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Create Clustered Index on ID CREATE CLUSTERED INDEX [IX_SecondTable_ID] ON SecondTable ( [ID] ASC ) ON [PRIMARY] GO -- Insert One Hundred Thousand Records INSERT INTO FirstTable (ID,FirstName,LastName,City) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 1 THEN 'New York' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 5 THEN 'San Marino' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 3 THEN 'Los Angeles' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Insert One Hundred Thousand Records INSERT INTO SecondTable (ID,FirstName,LastName,City) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 1 THEN 'New York' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 5 THEN 'San Marino' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 3 THEN 'Los Angeles' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO Let us check the table size and fragmentation. Now let us TRUNCATE the table and check the size and Fragmentation. USE MASTER GO CREATE DATABASE ShrinkIsBed GO USE ShrinkIsBed GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Create FirstTable CREATE TABLE FirstTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Create Clustered Index on ID CREATE CLUSTERED INDEX [IX_FirstTable_ID] ON FirstTable ( [ID] ASC ) ON [PRIMARY] GO -- Create SecondTable CREATE TABLE SecondTable (ID INT, FirstName VARCHAR(100), LastName VARCHAR(100), City VARCHAR(100)) GO -- Create Clustered Index on ID CREATE CLUSTERED INDEX [IX_SecondTable_ID] ON SecondTable ( [ID] ASC ) ON [PRIMARY] GO -- Insert One Hundred Thousand Records INSERT INTO FirstTable (ID,FirstName,LastName,City) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 1 THEN 'New York' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 5 THEN 'San Marino' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 3 THEN 'Los Angeles' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Insert One Hundred Thousand Records INSERT INTO SecondTable (ID,FirstName,LastName,City) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY a.name) RowID, 'Bob', CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%2 = 1 THEN 'Smith' ELSE 'Brown' END, CASE WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 1 THEN 'New York' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 5 THEN 'San Marino' WHEN ROW_NUMBER() OVER (ORDER BY a.name)%10 = 3 THEN 'Los Angeles' ELSE 'Houston' END FROM sys.all_objects a CROSS JOIN sys.all_objects b GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO You can clearly see that after TRUNCATE, the size of the database is not reduced and it is still the same as before TRUNCATE operation. After the Shrinking database operation, we were able to reduce the size of the database. If you notice the fragmentation, it is considerably high. The major problem with the Shrink operation is that it increases fragmentation of the database to very high value. Higher fragmentation reduces the performance of the database as reading from that particular table becomes very expensive. One of the ways to reduce the fragmentation is to rebuild index on the database. Let us rebuild the index and observe fragmentation and database size. -- Rebuild Index on FirstTable ALTER INDEX IX_SecondTable_ID ON SecondTable REBUILD GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO You can notice that after rebuilding, Fragmentation reduces to a very low value (almost same to original value); however the database size increases way higher than the original. Before rebuilding, the size of the database was 5 MB, and after rebuilding, it is around 20 MB. Regular rebuilding the index is rebuild in the same user database where the index is placed. This usually increases the size of the database. Look at irony of the Shrinking database. One person shrinks the database to gain space (thinking it will help performance), which leads to increase in fragmentation (reducing performance). To reduce the fragmentation, one rebuilds index, which leads to size of the database to increase way more than the original size of the database (before shrinking). Well, by Shrinking, one did not gain what he was looking for usually. Rebuild indexing is not the best suggestion as that will create database grow again. I have always remembered the excellent post from Paul Randal regarding Shrinking the database is bad. I suggest every one to read that for accuracy and interesting conversation. Let us run following script where we Shrink the database and REORGANIZE. -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO -- Shrink the Database DBCC SHRINKDATABASE (ShrinkIsBed); GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO -- Rebuild Index on FirstTable ALTER INDEX IX_SecondTable_ID ON SecondTable REORGANIZE GO -- Name of the Database and Size SELECT name, (size*8) Size_KB FROM sys.database_files GO -- Check Fragmentations in the database SELECT avg_fragmentation_in_percent, fragment_count FROM sys.dm_db_index_physical_stats (DB_ID(), OBJECT_ID('SecondTable'), NULL, NULL, 'LIMITED') GO You can see that REORGANIZE does not increase the size of the database or remove the fragmentation. Again, I no way suggest that REORGANIZE is the solution over here. This is purely observation using demo. Read the blog post of Paul Randal. Following script will clean up the database -- Clean up USE MASTER GO ALTER DATABASE ShrinkIsBed SET SINGLE_USER WITH ROLLBACK IMMEDIATE GO DROP DATABASE ShrinkIsBed GO There are few valid cases of the Shrinking database as well, but that is not covered in this blog post. We will cover that area some other time in future. Additionally, one can rebuild index in the tempdb as well, and we will also talk about the same in future. Brent has written a good summary blog post as well. Are you Shrinking your database? Well, when are you going to stop Shrinking it? Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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• Testing Workflows &ndash; Test-After

  - by Timothy Klenke

  Originally posted on: http://geekswithblogs.net/TimothyK/archive/2014/05/30/testing-workflows-ndash-test-after.aspxIn this post I’m going to outline a few common methods that can be used to increase the coverage of of your test suite.  This won’t be yet another post on why you should be doing testing; there are plenty of those types of posts already out there.  Assuming you know you should be testing, then comes the problem of how do I actual fit that into my day job.  When the opportunity to automate testing comes do you take it, or do you even recognize it? There are a lot of ways (workflows) to go about creating automated tests, just like there are many workflows to writing a program.  When writing a program you can do it from a top-down approach where you write the main skeleton of the algorithm and call out to dummy stub functions, or a bottom-up approach where the low level functionality is fully implement before it is quickly wired together at the end.  Both approaches are perfectly valid under certain contexts. Each approach you are skilled at applying is another tool in your tool belt.  The more vectors of attack you have on a problem – the better.  So here is a short, incomplete list of some of the workflows that can be applied to increasing the amount of automation in your testing and level of quality in general.  Think of each workflow as an opportunity that is available for you to take. Test workflows basically fall into 2 categories:  test first or test after.  Test first is the best approach.  However, this post isn’t about the one and only best approach.  I want to focus more on the lesser known, less ideal approaches that still provide an opportunity for adding tests.  In this post I’ll enumerate some test-after workflows.  In my next post I’ll cover test-first. Bug Reporting When someone calls you up or forwards you a email with a vague description of a bug its usually standard procedure to create or verify a reproduction plan for the bug via manual testing and log that in a bug tracking system.  This can be problematic.  Often reproduction plans when written down might skip a step that seemed obvious to the tester at the time or they might be missing some crucial environment setting. Instead of data entry into a bug tracking system, try opening up the test project and adding a failing unit test to prove the bug.  The test project guarantees that all aspects of the environment are setup properly and no steps are missing.  The language in the test project is much more precise than the English that goes into a bug tracking system. This workflow can easily be extended for Enhancement Requests as well as Bug Reporting. Exploratory Testing Exploratory testing comes in when you aren’t sure how the system will behave in a new scenario.  The scenario wasn’t planned for in the initial system requirements and there isn’t an existing test for it.  By definition the system behaviour is “undefined”. So write a new unit test to define that behaviour.  Add assertions to the tests to confirm your assumptions.  The new test becomes part of the living system specification that is kept up to date with the test suite. Examples This workflow is especially good when developing APIs.  When you are finally done your production API then comes the job of writing documentation on how to consume the API.  Good documentation will also include code examples.  Don’t let these code examples merely exist in some accompanying manual; implement them in a test suite. Example tests and documentation do not have to be created after the production API is complete.  It is best to write the example code (tests) as you go just before the production code. Smoke Tests Every system has a typical use case.  This represents the basic, core functionality of the system.  If this fails after an upgrade the end users will be hosed and they will be scratching their heads as to how it could be possible that an update got released with this core functionality broken. The tests for this core functionality are referred to as “smoke tests”.  It is a good idea to have them automated and run with each build in order to avoid extreme embarrassment and angry customers. Coverage Analysis Code coverage analysis is a tool that reports how much of the production code base is exercised by the test suite.  In Visual Studio this can be found under the Test main menu item. The tool will report a total number for the code coverage, which can be anywhere between 0 and 100%.  Coverage Analysis shouldn’t be used strictly for numbers reporting.  Companies shouldn’t set minimum coverage targets that mandate that all projects must have at least 80% or 100% test coverage.  These arbitrary requirements just invite gaming of the coverage analysis, which makes the numbers useless. The analysis tool will break down the coverage by the various classes and methods in projects.  Instead of focusing on the total number, drill down into this view and see which classes have high or low coverage.  It you are surprised by a low number on a class this is an opportunity to add tests. When drilling through the classes there will be generally two types of reaction to a surprising low test coverage number.  The first reaction type is a recognition that there is low hanging fruit to be picked.  There may be some classes or methods that aren’t being tested, which could easy be.  The other reaction type is “OMG”.  This were you find a critical piece of code that isn’t under test.  In both cases, go and add the missing tests. Test Refactoring The general theme of this post up to this point has been how to add more and more tests to a test suite.  I’ll step back from that a bit and remind that every line of code is a liability.  Each line of code has to be read and maintained, which costs money.  This is true regardless whether the code is production code or test code. Remember that the primary goal of the test suite is that it be easy to read so that people can easily determine the specifications of the system.  Make sure that adding more and more tests doesn’t interfere with this primary goal. Perform code reviews on the test suite as often as on production code.  Hold the test code up to the same high readability standards as the production code.  If the tests are hard to read then change them.  Look to remove duplication.  Duplicate setup code between two or more test methods that can be moved to a shared function.  Entire test methods can be removed if it is found that the scenario it tests is covered by other tests.  Its OK to delete a test that isn’t pulling its own weight anymore. Remember to only start refactoring when all the test are green.  Don’t refactor the tests and the production code at the same time.  An automated test suite can be thought of as a double entry book keeping system.  The unchanging, passing production code serves as the tests for the test suite while refactoring the tests. As with all refactoring, it is best to fit this into your regular work rather than asking for time later to get it done.  Fit this into the standard red-green-refactor cycle.  The refactor step no only applies to production code but also the tests, but not at the same time.  Perhaps the cycle should be called red-green-refactor production-refactor tests (not quite as catchy).   That about covers most of the test-after workflows I can think of.  In my next post I’ll get into test-first workflows.

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• Installer Reboots at "Detecting hardware" (disks and other hardware) on all recent Server Installs

  - by Ryan Rosario

  I have a very frustrating problem with my PC. I cannot install any recent version of Ubuntu Server (or even Desktop) since 9.04 even using the text-based installer. I boot from a USB stick created by Unetbootin (I also tried other methods such as startup disk creator with no difference). On the Server installer, it gets to "Detecting Hardware" (the second one about disks and all other hardware, not network hardware) and then either hangs at 0% (waited 24 hours), or reboots after a minute or two. My system (late 2007): ASUS P5NSLI motherboard Intel Core 2 Duo E6600 2.4Ghz 2 x 1GB Corsair 667MHz RAM nVidia GeForce 6600 I have unplugged everything (including the only hard disk, CD-ROMs and floppy). I have only one stick of RAM (tried each one to no avail) and am booting the installer from a USB stick (booting from CD-ROM yields the same problem). I also tried several of the boot options (nomodeset, nousb, acpi=off, noapic, i915.modeset=1/0, xforcevesa) in all combinations) to no avail. The only active parts of my system are the video card, mouse, keyboard and USB stick. I have also updated the BIOS to the most recent version. (FWIW, on the Desktop installer, I get a black screen after hitting the Install option.) Even after removing "quiet" I am unable to see what kernel panic is occurring (or not occurring) to cause the install to crash. I am only able to save the debug logs via a simple webserver in the installer. After the last line (I repeatedly refreshed), the server stops responding and the installer hangs or reboots: Jan 2 01:04:03 main-menu[302]: INFO: Menu item 'disk-detect' selected Jan 2 01:04:04 kernel: [ 309.154372] sata_nv 0000:00:0e.0: version 3.5 Jan 2 01:04:04 kernel: [ 309.154409] sata_nv 0000:00:0e.0: Using SWNCQ mode Jan 2 01:04:04 kernel: [ 309.154531] sata_nv 0000:00:0e.0: setting latency timer to 64 Jan 2 01:04:04 kernel: [ 309.164442] scsi0 : sata_nv Jan 2 01:04:04 kernel: [ 309.167610] scsi1 : sata_nv Jan 2 01:04:04 kernel: [ 309.167762] ata1: SATA max UDMA/133 cmd 0x9f0 ctl 0xbf0 bmdma 0xd400 irq 10 Jan 2 01:04:04 kernel: [ 309.167774] ata2: SATA max UDMA/133 cmd 0x970 ctl 0xb70 bmdma 0xd408 irq 10 Jan 2 01:04:04 kernel: [ 309.167948] sata_nv 0000:00:0f.0: Using SWNCQ mode Jan 2 01:04:04 kernel: [ 309.168071] sata_nv 0000:00:0f.0: setting latency timer to 64 Jan 2 01:04:04 kernel: [ 309.171931] scsi2 : sata_nv Jan 2 01:04:04 kernel: [ 309.173793] scsi3 : sata_nv Jan 2 01:04:04 kernel: [ 309.173943] ata3: SATA max UDMA/133 cmd 0x9e0 ctl 0xbe0 bmdma 0xe800 irq 11 Jan 2 01:04:04 kernel: [ 309.173954] ata4: SATA max UDMA/133 cmd 0x960 ctl 0xb60 bmdma 0xe808 irq 11 Jan 2 01:04:04 kernel: [ 309.174061] pata_amd 0000:00:0d.0: version 0.4.1 Jan 2 01:04:04 kernel: [ 309.174160] pata_amd 0000:00:0d.0: setting latency timer to 64 Jan 2 01:04:04 kernel: [ 309.177045] scsi4 : pata_amd Jan 2 01:04:04 kernel: [ 309.178628] scsi5 : pata_amd Jan 2 01:04:04 kernel: [ 309.178801] ata5: PATA max UDMA/133 cmd 0x1f0 ctl 0x3f6 bmdma 0xf000 irq 14 Jan 2 01:04:04 kernel: [ 309.178811] ata6: PATA max UDMA/133 cmd 0x170 ctl 0x376 bmdma 0xf008 irq 15 Jan 2 01:04:04 net/hw-detect.hotplug: Detected hotpluggable network interface eth0 Jan 2 01:04:04 net/hw-detect.hotplug: Detected hotpluggable network interface lo Jan 2 01:04:04 kernel: [ 309.485062] ata3: SATA link down (SStatus 0 SControl 300) Jan 2 01:04:04 kernel: [ 309.633094] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Jan 2 01:04:04 kernel: [ 309.641647] ata1.00: ATA-8: ST31000528AS, CC38, max UDMA/133 Jan 2 01:04:04 kernel: [ 309.641658] ata1.00: 1953525168 sectors, multi 1: LBA48 NCQ (depth 31/32) Jan 2 01:04:04 kernel: [ 309.657614] ata1.00: configured for UDMA/133 Jan 2 01:04:04 kernel: [ 309.657969] scsi 0:0:0:0: Direct-Access ATA ST31000528AS CC38 PQ: 0 ANSI: 5 Jan 2 01:04:04 kernel: [ 309.658482] sd 0:0:0:0: Attached scsi generic sg0 type 0 Jan 2 01:04:04 kernel: [ 309.658588] sd 0:0:0:0: [sda] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) Jan 2 01:04:04 kernel: [ 309.658812] sd 0:0:0:0: [sda] Write Protect is off Jan 2 01:04:04 kernel: [ 309.658823] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 Jan 2 01:04:04 kernel: [ 309.658918] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jan 2 01:04:04 kernel: [ 309.675630] sda: sda1 sda2 Jan 2 01:04:04 kernel: [ 309.676440] sd 0:0:0:0: [sda] Attached SCSI disk Jan 2 01:04:05 kernel: [ 309.969102] ata2: SATA link down (SStatus 0 SControl 300) Jan 2 01:04:05 kernel: [ 310.281137] ata4: SATA link down (SStatus 0 SControl 300) Anybody have any additional ideas I could try? I am getting ready to just toss the motherboard.

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• OBIEE 11.1.1 - User Interface (UI) Performance Is Slow With Internet Explorer 8

  - by Ahmed A

  The OBIEE 11g UI is performance is slow in IE 8 and faster in Firefox.  For VPN or WAN users, it takes long time to display links on Dashboards via IE 8. Cause is IE 8 generates many HTTP 304 return calls and this caused the 11g UI slower when compared to the Mozilla FireFox browser. To resolve this issue, you can implement HTTP compression and caching. This is a best practice.Why use Web Server Compression / Caching for OBIEE? Bandwidth Savings: Enabling HTTP compression can have a dramatic improvement on the latency of responses. By compressing static files and dynamic application responses, it will significantly reduce the remote (high latency) user response time. Improves request/response latency: Caching makes it possible to suppress the payload of the HTTP reply using the 304 status code.  Minimizing round trips over the Web to re-validate cached items can make a huge difference in browser page load times. This screen shot depicts the flow and where the compression and decompression occurs: Solution: a. How to Enable HTTP Caching / Compression in Oracle HTTP Server (OHS) 11.1.1.x 1. To implement HTTP compression / caching, install and configure Oracle HTTP Server (OHS) 11.1.1.x for the bi_serverN Managed Servers (refer to "OBIEE Enterprise Deployment Guide for Oracle Business Intelligence" document for details). 2. On the OHS machine, open the file HTTP Server configuration file (httpd.conf) for editing. This file is located in the OHS installation directory.For example: ORACLE_HOME/Oracle_WT1/instances/instance1/config/OHS/ohs13. In httpd.conf file, verify that the following directives are included and not commented out: LoadModule expires_module "${ORACLE_HOME}/ohs/modules/mod_expires.soLoadModule deflate_module "${ORACLE_HOME}/ohs/modules/mod_deflate.so 4. Add the following lines in httpd.conf file below the directive LoadModule section and restart the OHS: Note: For the Windows platform, you will need to enclose any paths in double quotes ("), for example:Alias "/analytics ORACLE_HOME/bifoundation/web/app"<Directory "ORACLE_HOME/bifoundation/web/app"> Alias /analytics ORACLE_HOME/bifoundation/web/app#Pls replace the ORACLE_HOME with your actual BI ORACLE_HOME path<Directory ORACLE_HOME/bifoundation/web/app>#We don't generate proper cross server ETags so disable themFileETag noneSetOutputFilter DEFLATE# Don't compress imagesSetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary<FilesMatch "\.(gif|jpeg|png|js|x-javascript|javascript|css)$">#Enable future expiry of static filesExpiresActive onExpiresDefault "access plus 1 week"     #1 week, this will stops the HTTP304 calls i.e. generated by IE 8Header set Cache-Control "max-age=604800"</FilesMatch>DirectoryIndex default.jsp</Directory>#Restrict access to WEB-INF<Location /analytics/WEB-INF>Order Allow,DenyDeny from all</Location> Note: Make sure you replace above placeholder "ORACLE_HOME" to your correct path for BI ORACLE_HOME.For example: my BI Oracle Home path is /Oracle/BIEE11g/Oracle_BI1/bifoundation/web/app Important Notes: Above caching rules restricted to static files found inside the /analytics directory(/web/app). This approach is safer instead of setting static file caching globally. In some customer environments you may not get 100% performance gains in IE 8.0 browser. So in that case you need to extend caching rules to other directories with static files content. If OHS is installed on separate dedicated machine, make sure static files in your BI ORACLE_HOME (../Oracle_BI1/bifoundation/web/app) is accessible to the OHS instance. The following screen shot summarizes the before and after results and improvements after enabling compression and caching:

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• Database – Beginning with Cloud Database As A Service

  - by Pinal Dave

  I love my weekend projects. Everybody does different activities in their weekend – like traveling, reading or just nothing. Every weekend I try to do something creative and different in the database world. The goal is I learn something new and if I enjoy my learning experience I share with the world. This weekend, I decided to explore Cloud Database As A Service – Morpheus. In my career I have managed many databases in the cloud and I have good experience in managing them. I should highlight that today’s applications use multiple databases from SQL for transactions and analytics, NoSQL for documents, In-Memory for caching to Indexing for search.  Provisioning and deploying these databases often require extensive expertise and time.  Often these databases are also not deployed on the same infrastructure and can create unnecessary latency between the application layer and the databases.  Not to mention the different quality of service based on the infrastructure and the service provider where they are deployed. Moreover, there are additional problems that I have experienced with traditional database setup when hosted in the cloud: Database provisioning & orchestration Slow speed due to hardware issues Poor Monitoring Tools High network latency Now if you have a great software and expert network engineer, you can continuously work on above problems and overcome them. However, not every organization have the luxury to have top notch experts in the field. Now above issues are related to infrastructure, but there are a few more problems which are related to software/application as well. Here are the top three things which can be problems if you do not have application expert: Replication and Clustering Simple provisioning of the hard drive space Automatic Sharding Well, Morpheus looks like a product build by experts who have faced similar situation in the past. The product pretty much addresses all the pain points of developers and database administrators. What is different about Morpheus is that it offers a variety of databases from MySQL, MongoDB, ElasticSearch to Reddis as a service.  Thus users can pick and chose any combination of these databases.  All of them can be provisioned in a matter of minutes with a simple and intuitive point and click user interface.  The Morpheus cloud is built on Solid State Drives (SSD) and is designed for high-speed database transactions.  In addition it offers a direct link to Amazon Web Services to minimize latency between the application layer and the databases. Here are the few steps on how one can get started with Morpheus. Follow along with me.  First go to http://www.gomorpheus.com and register for a new and free account. Step 1: Signup It is very simple to signup for Morpheus. Step 2: Select your database   I use MySQL for my daily routine, so I have selected MySQL. Upon clicking on the big red button to add Instance, it prompted a dialogue of creating a new instance.   Step 3: Create User Now we just have to create a user in our portal which we will use to connect to a database hosted at Morpheus. Click on your database instance and it will bring you to User Screen. Over here you will notice once again a big red button to create a new user. I created a user with my first name.   Step 4: Configure your MySQL client I used MySQL workbench and connected to MySQL instance, which I had created with an IP address and user.   That’s it! You are connecting to MySQL instance. Now you can create your objects just like you would create on your local box. You will have all the features of the Morpheus when you are working with your database. Dashboard While working with Morpheus, I was most impressed with its dashboard. In future blog posts, I will write more about this feature.  Also with Morpheus you use the same process for provisioning and connecting with other databases: MongoDB, ElasticSearch and Reddis. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• MySQL Cluster 7.3: On-Demand Webinar and Q&A Available

  - by Mat Keep

  The on-demand webinar for the MySQL Cluster 7.3 Development Release is now available. You can learn more about the design, implementation and getting started with all of the new MySQL Cluster 7.3 features from the comfort and convenience of your own device, including: - Foreign Key constraints in MySQL Cluster - Node.js NoSQL API  - Auto-installation of higher performance distributed, clusters We received some great questions over the course of the webinar, and I wanted to share those for the benefit of a broader audience. Q. What Foreign Key actions are supported: A. The core referential actions defined in the SQL:2003 standard are implemented: CASCADE RESTRICT NO ACTION SET NULL Q. Where are Foreign Keys implemented, ie data nodes or SQL nodes? A. They are implemented in the data nodes, therefore can be enforced for both the SQL and NoSQL APIs Q. Are they compatible with the InnoDB Foreign Key implementation? A. Yes, with the following exceptions: - InnoDB doesn’t support “No Action” constraints, MySQL Cluster does - You can choose to suspend FK constraint enforcement with InnoDB using the FOREIGN_KEY_CHECKS parameter; at the moment, MySQL Cluster ignores that parameter. - You cannot set up FKs between 2 tables where one is stored using MySQL Cluster and the other InnoDB. - You cannot change primary keys through the NDB API which means that the MySQL Server actually has to simulate such operations by deleting and re-adding the row. If the PK in the parent table has a FK constraint on it then this causes non-ideal behaviour. With Restrict or No Action constraints, the change will result in an error. With Cascaded constraints, you’d want the rows in the child table to be updated with the new FK value but, the implicit delete of the row from the parent table would remove the associated rows from the child table and the subsequent implicit insert into the parent wouldn’t reinstate the child rows. For this reason, an attempt to add an ON UPDATE CASCADE where the parent column is a primary key will be rejected. Q. Does adding or dropping Foreign Keys cause downtime due to a schema change? A. Nope, this is an online operation. MySQL Cluster supports a number of on-line schema changes, ie adding and dropping indexes, adding columns, etc. Q. Where can I see an example of node.js with MySQL Cluster? A. Check out the tutorial and download the code from GitHub Q. Can I use the auto-installer to support remote deployments? How about setting up MySQL Cluster 7.2? A. Yes to both! Q. Can I get a demo Check out the tutorial. You can download the code from http://labs.mysql.com/ Go to Select Build drop-down box Q. What is be minimum internet speen required for Geo distributed cluster with synchronous replication? A. if you're splitting you cluster between sites then we recommend a network latency of 20ms or less. Alternatively, use MySQL asynchronous replication where the latency of your WAN doesn't impact the latency of your reads/writes. Q. Where you can one learn more about the PayPal project with MySQL Cluster? A. Take a look at the following - you'll find press coverage, a video and slides from their keynote presentation  So, if you want to learn more, listen to the new MySQL Cluster 7.3 on-demand webinar  MySQL Cluster 7.3 is still in the development phase, so it would be great to get your feedback on these new features, and things you want to see!

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• The enterprise vendor con - connecting SSD's using SATA 2 (3Gbits) thus limiting there performance

  - by tonyrogerson

  When comparing SSD against Hard drive performance it really makes me cross when folk think comparing an array of SSD running on 3GBits/sec to hard drives running on 6GBits/second is somehow valid. In a paper from DELL (http://www.dell.com/downloads/global/products/pvaul/en/PowerEdge-PowerVaultH800-CacheCade-final.pdf) on increasing database performance using the DELL PERC H800 with Solid State Drives they compare four SSD drives connected at 3Gbits/sec against ten 10Krpm drives connected at 6Gbits [Tony slaps forehead while shouting DOH!]. It is true in the case of hard drives it probably doesn’t make much difference 3Gbit or 6Gbit because SAS and SATA are both end to end protocols rather than shared bus architecture like SCSI, so the hard drive doesn’t share bandwidth and probably can’t get near the 600MiBytes/second throughput that 6Gbit gives unless you are doing contiguous reads, in my own tests on a single 15Krpm SAS disk using IOMeter (8 worker threads, queue depth of 16 with a stripe size of 64KiB, an 8KiB transfer size on a drive formatted with an allocation size of 8KiB for a 100% sequential read test) I only get 347MiBytes per second sustained throughput at an average latency of 2.87ms per IO equating to 44.5K IOps, ok, if that was 3GBits it would be less – around 280MiBytes per second, oh, but wait a minute [...fingers tap desk] You’ll struggle to find in the commodity space an SSD that doesn’t have the SATA 3 (6GBits) interface, SSD’s are fast not only low latency and high IOps but they also offer a very large sustained transfer rate, consider the OCZ Agility 3 it so happens that in my masters dissertation I did the same test but on a difference box, I got 374MiBytes per second at an average latency of 2.67ms per IO equating to 47.9K IOps – cost of an 240GB Agility 3 is £174.24 (http://www.scan.co.uk/products/240gb-ocz-agility-3-ssd-25-sata-6gb-s-sandforce-2281-read-525mb-s-write-500mb-s-85k-iops), but that same drive set in a box connected with SATA 2 (3Gbits) would only yield around 280MiBytes per second thus losing almost 100MiBytes per second throughput and a ton of IOps too. So why the hell are “enterprise” vendors still only connecting SSD’s at 3GBits? Well, my conspiracy states that they have no interest in you moving to SSD because they’ll lose so much money, the argument that they use SATA 2 doesn’t wash, SATA 3 has been out for some time now and all the commodity stuff you buy uses it now. Consider the cost, not in terms of price per GB but price per IOps, SSD absolutely thrash Hard Drives on that, it was true that the opposite was also true that Hard Drives thrashed SSD’s on price per GB, but is that true now, I’m not so sure – a 300GByte 2.5” 15Krpm SAS drive costs £329.76 ex VAT (http://www.scan.co.uk/products/300gb-seagate-st9300653ss-savvio-15k3-25-hdd-sas-6gb-s-15000rpm-64mb-cache-27ms) which equates to £1.09 per GB compared to a 480GB OCZ Agility 3 costing £422.10 ex VAT (http://www.scan.co.uk/products/480gb-ocz-agility-3-ssd-25-sata-6gb-s-sandforce-2281-read-525mb-s-write-410mb-s-30k-iops) which equates to £0.88 per GB. Ok, I compared an “enterprise” hard drive with a “commodity” SSD, ok, so things get a little more complicated here, most “enterprise” SSD’s are SLC and most commodity are MLC, SLC gives more performance and wear, I’ll talk about that another day. For now though, don’t get sucked in by vendor marketing, SATA 2 (3Gbit) just doesn’t cut it, SSD need 6Gbit to breath and even that SSD’s are pushing. Alas, SSD’s are connected using SATA so all the controllers I’ve seen thus far from HP and DELL only do SATA 2 – deliberate? Well, I’ll let you decide on that one.

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• Recent improvements in Console Performance

  - by loren.konkus

  Recently, the WebLogic Server development and support organizations have worked with a number of customers to quantify and improve the performance of the Administration Console in large, distributed configurations where there is significant latency in the communications between the administration server and managed servers. These improvements fall into two categories: Constraining the amount of time that the Console stalls waiting for communication Reducing and streamlining the amount of data required for an update A few releases ago, we added support for a configurable domain-wide mbean "Invocation Timeout" value on the Console's configuration: general, advanced section for a domain. The default value for this setting is 0, which means wait indefinitely and was chosen for compatibility with the behavior of previous releases. This configuration setting applies to all mbean communications between the admin server and managed servers, and is the first line of defense against being blocked by a stalled or completely overloaded managed server. Each site should choose an appropriate timeout value for their environment and network latency. In the next release of WebLogic Server, we've added an additional console preference, "Management Operation Timeout", to the Console's shared preference page. This setting further constrains how long certain console pages will wait for slowly responding servers before returning partial results. While not all Console pages support this yet, key pages such as the Servers Configuration and Control table pages and the Deployments Control pages have been updated to support this. For example, if a user requests a Servers Table page and a Management Operation Timeout occurs, the table is displayed with both local configuration and remote runtime information from the responding managed servers and only local configuration information for servers that did not yet respond. This means that a troublesome managed server does not impede your ability to manage your domain using the Console. To support these changes, these Console pages have been re-written to use the Work Management feature of WebLogic Server to interact with each server or deployment concurrently, which further improves the responsiveness of these pages. The basic algorithm for these pages is: For each configuration mbean (ie, Servers) populate rows with configuration attributes from the fast, local mbean server Find a WorkManager For each server, Create a Work instance to obtain runtime mbean attributes for the server Schedule Work instance in the WorkManager Call WorkManager.waitForAll to wait WorkItems to finish, constrained by Management Operation Timeout For each WorkItem, if the runtime information obtained was not complete, add a message indicating which server has incomplete data Display collected data in table In addition to these changes to constrain how long the console waits for communication, a number of other changes have been made to reduce the amount and scope of managed server interactions for key pages. For example, in previous releases the Deployments Control table looked at the status of a deployment on every managed server, even those servers that the deployment was not currently targeted on. (This was done to handle an edge case where a deployment's target configuration was changed while it remained running on previously targeted servers.) We decided supporting that edge case did not warrant the performance impact for all, and instead only look at the status of a deployment on the servers it is targeted to. Comprehensive status continues to be available if a user clicks on the 'status' field for a deployment. Finally, changes have been made to the System Status portlet to reduce its impact on Console page display times. Obtaining health information for this display requires several mbean interactions with managed servers. In previous releases, this mbean interaction occurred with every display, and any delay or impediment in these interactions was reflected in the display time for every page. To reduce this impact, we've made several changes in this portlet: Using Work Management to obtain health concurrently Applying the operation timeout configuration to constrain how long we will wait Caching health information to reduce the cost during rapid navigation from page to page and only obtaining new health information if the previous information is over 30 seconds old. Eliminating heath collection if this portlet is minimized. Together, these Console changes have resulted in significant performance improvements for the customers with large configurations and high latency that we have worked with during their development, and some lesser performance improvements for those with small configurations and very fast networks. These changes will be included in the 11g Rel 1 patch set 2 (10.3.3.0) release of WebLogic Server.

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• Best Practices - Core allocation

  - by jsavit

  This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (also called Logical Domains) Introduction SPARC T-series servers currently have up to 4 CPU sockets, each of which has up to 8 or (on SPARC T3) 16 CPU cores, while each CPU core has 8 threads, for a maximum of 512 dispatchable CPUs. The defining feature of Oracle VM Server for SPARC is that each domain is assigned CPU threads or cores for its exclusive use. This avoids the overhead of software-based time-slicing and emulation (or binary rewriting) of system state-changing privileged instructions used in traditional hypervisors. To create a domain, administrators specify either the number of CPU threads or cores that the domain will own, as well as its memory and I/O resources. When CPU resources are assigned at the individual thread level, the logical domains constraint manager attempts to assign threads from the same cores to a domain, and avoid "split core" situations where the same CPU core is used by multiple domains. Sometimes this is unavoidable, especially when domains are allocated and deallocated CPUs in small increments. Why split cores can matter Split core allocations can silenty reduce performance because multiple domains with different address spaces and memory contents are sharing the core's Level 1 cache (L1$). This is called false cache sharing since even identical memory addresses from different domains must point to different locations in RAM. The effect of this is increased contention for the cache, and higher memory latency for each domain using that core. The degree of performance impact can be widely variable. For applications with very small memory working sets, and with I/O bound or low-CPU utilization workloads, it may not matter at all: all machines wait for work at the same speed. If the domains have substantial workloads, or are critical to performance then this can have an important impact: This blog entry was inspired by a customer issue in which one CPU core was split among 3 domains, one of which was the control and service domain. The reported problem was increased I/O latency in guest domains, but the root cause might be higher latency servicing the I/O requests due to the control domain being slowed down. What to do about it Split core situations are easily avoided. In most cases the logical domain constraint manager will avoid it without any administrative action, but it can be entirely prevented by doing one of the several actions: Assign virtual CPUs in multiples of 8 - the number of threads per core. For example: ldm set-vcpu 8 mydomain or ldm add-vcpu 24 mydomain. Each domain will then be allocated on a core boundary. Use the whole core constraint when assigning CPU resources. This allocates CPUs in increments of entire cores instead of virtual CPU threads. The equivalent of the above commands would be ldm set-core 1 mydomain or ldm add-core 3 mydomain. Older syntax does the same thing by adding the -c flag to the add-vcpu, rm-vcpu and set-vcpu commands, but the new syntax is recommended. When whole core allocation is used an attempt to add cores to a domain fails if there aren't enough completely empty cores to satisfy the request. See https://blogs.oracle.com/sharakan/entry/oracle_vm_server_for_sparc4 for an excellent article on this topic by Eric Sharakan. Don't obsess: - if the workloads have minimal CPU requirements and don't need anywhere near a full CPU core, then don't worry about it. If you have low utilization workloads being consolidated from older machines onto a current T-series, then there's no need to worry about this or to assign an entire core to domains that will never use that much capacity. In any case, make sure the most important domains have their own CPU cores, in particular the control domain and any I/O or service domain, and of course any important guests. Summary Split core CPU allocation to domains can potentially have an impact on performance, but the logical domains manager tends to prevent this situation, and it can be completely and simply avoided by allocating virtual CPUs on core boundaries.

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• How the SPARC T4 Processor Optimizes Throughput Capacity: A Case Study

  - by Ruud

  This white paper demonstrates the architected latency hiding features of Oracle’s UltraSPARC T2+ and SPARC T4 processors That is the first sentence from this technical white paper, but what does it exactly mean? Let's consider a very simple example, the computation of a = b + c. This boils down to the following (pseudo-assembler) instructions that need to be executed: load @b, r1 load @c, r2 add r1,r2,r3 store r3, @a The first two instructions load variables b and c from an address in memory (here symbolized by @b and @c respectively). These values go into registers r1 and r2. The third instruction adds the values in r1 and r2. The result goes into register r3. The fourth instruction stores the contents of r3 into the memory address symbolized by @a. If we're lucky, both b and c are in a nearby cache and the load instructions only take a few processor cycles to execute. That is the good case, but what if b or c, or both, have to come from very far away? Perhaps both of them are in the main memory and then it easily takes hundreds of cycles for the values to arrive in the registers. Meanwhile the processor is doing nothing and simply waits for the data to arrive. Actually, it does something. It burns cycles while waiting. That is a waste of time and energy. Why not use these cycles to execute instructions from another application or thread in case of a parallel program? That is exactly what latency hiding on the SPARC T-Series processors does. It is a hardware feature totally transparent to the user and application. As soon as there is a delay in the execution, the hardware uses these otherwise idle cycles to execute instructions from another process. As a result, the throughput capacity of the system improves because idle cycles are no longer wasted and therefore more jobs can be run per unit of time. This feature has been in the SPARC T-series from the beginning, so why this paper? The difference with previous publications on this topic is in the amount of detail given. How this all works under the hood is fully explained using two example programs. Starting from the assembly language instructions, it is demonstrated in what way these programs execute. To really see what is happening we go down to the processor pipeline level, where the gaps in the execution are, and show in what way these idle cycles are filled by other copies of the same program running simultaneously. Both the SPARC T4 as well as the older UltraSPARC T2+ processor are covered. You may wonder why the UltraSPARC T2+ is included. The focus of this work is on the SPARC T4 processor, but to explain the basic concept of latency hiding at this very low level, we start with the UltraSPARC T2+ processor because it is architecturally a much simpler design. From the single issue, in-order pipelines of this processor we then shift gears and cover how this all works on the much more advanced dual issue, out-of-order architecture of the T4. The analysis and performance experiments have been conducted on both processors. The results depend on the processor, but in all cases the theoretical estimates are confirmed by the experiments. If you're interested to read a lot more about this and find out how things really work under the hood, you can download a copy of the paper here. A paper like this could not have been produced without the help of several other people. I want to thank the co-author of this paper, Jared Smolens, for his very valuable contributions and our highly inspiring discussions. I'm also indebted to Thomas Nau (Ulm University, Germany), Shane Sigler and Mark Woodyard (both at Oracle) for their feedback on earlier versions of this paper. Karen Perkins (Perkins Technical Writing and Editing) and Rick Ramsey at Oracle were very helpful in providing editorial and publishing assistance.

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• Bios Memory settings and Virtualization + Ubuntu (Unofficial Answers Welcome) [closed]

  - by TardisGuy

  Attempting to optimize my (Main Windowless) Ubuntu system for my uses I will detail questions below, I understand this might be the wrong place to ask these questions. If so, my apologies and I thank you so much for your patience. Thanks to all the volenteers that have helped me learn ubuntu over the years (Since 5.10) This is a "short" list of questions I have been trying to figure out for some time. If you feel you can answer one but not another, that's already more than I could ask for. I have wrote this up in a format for easy navigation to important points Hopefully to less annoy your eyes. You're welcome :) or i'm sorry i annoy you. :( If you would be so kind, Please format answers as follows: question 1: _ _ _ _ _ or question 1-a: _ _ _ _ _ If you want to simply link me to relevant information, rather than type up something really detailed; that would be more than awesome! Memory Specific Questions Goal: Maximizing memory bandwith to better perform in Virtualization, and Large file compression. (Possible conflict?) Ganged vs Unganged "which is better?"** is relative, i know. But what about ganged vs unganged - With or without Bank/channel interleaving? a: Speculation - If i understand correctly, "channel interleaving has something to do with using both channels to read or write in a kind of "striping" pattern, as opposed to a standard half duplex operation.(probably wrong) but wouldn't ganged channels make this irrelevant? Memory Interleaving(bank). Does it have a down side? Does it require a ratio of clocks? (If I run 4x4gig ddr3) a. If im reading correctly(trying to learn), this is designed to spread operations between latency cycles to work around the higher latency of "normal" operation. b. However it seems to me that it has to be: divisible by fractions of a master clock? So if i run memory at 1333mhz, then the mean between 2 (physical) banks would operate every (roughly) 600Mhz? Warning! Possibly utter nonsense: (1333/2 interleaving to act like 1 memory module per 2 sticks of a total of 4 sticks, meaning 2x channels@4) c. which makes me wonder if there would be left over clock cycles the system would have to... "truncate/balance" or something? But I'm certain theres a feature somewhere i don't understand. Virtualization Questions AMD-V - Option of IOMMU Turned it on, why do i have extra option of "64MB"? If IOMMU is on, but "64MB" is "disabled", Is it on? (have scoured google, I still dont know) a. I think i understand that its supposed to (kind of) "set aside" a part of ram to act as a faster interactive zone for "stuff" (usb, Graphics, and... what?) b. I am using Nvidia graphics on AMD (Used kernel option "iommu=pt iommu=1, pt "passthrough"? No idea what they do, found it on google to solve boot up issue) c. Will this option help me use low latency sound hardware, like my midi keyboard? Can you recommend any additional tweaks? a. sysctl settings? b. swap settings? Grats, youve reached the end. Thanks for Reading.

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• Replacement for Hamachi for SVN access

  - by Piers

  My company has been using Hamachi to access our SVN repository for a number of years. We are a small yet widely distributed development team with each programmer in a different country working from home. The server is hosted by a non-techie in our central office. Hamachi is useful here since it has a GUI and supports remote management. This system worked well for a while, but recently I have moved to a country with poor internet speeds. Hamachi will no longer connect 99% of the time - instead I get a "Probing..." message that doesn't resolve. It's certain to be a latency issue, as the same laptop will connect without problems when I cross the border and connect using a different ISP with better speeds. So I really need to replace Hamachi with some other VPN/protocol that handles latency better. The techie managing the repository is not comfortable installing and configuring Apache or IIS, so it looks like HTTP is out. I tried to convince my boss to go for a web hosting company, but he doesn't trust a 3rd party with our source. Any other recommended options / experiences out there for accessing our SVN repos that would be as simple as Hamachi for setup; but be more tolerant of network latency issues?

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• Problem using the find function in MATLAB

  - by Peter Etchells

  I have two arrays of data that I'm trying to amalgamate. One contains actual latencies from an experiment in the first column (e.g. 0.345, 0.455... never more than 3 decimal places), along with other data from that experiment. The other contains what is effectively a 'look up' list of latencies ranging from 0.001 to 0.500 in 0.001 increments, along with other pieces of data. Both data sets are X-by-Y doubles. What I'm trying to do is something like... for i = 1:length(actual_latency) row = find(predicted_data(:,1) == actual_latency(i)) full_set(i,1:4) = [actual_latency(i) other_info(i) predicted_info(row,2) ... predicted_info(row,3)]; end ...in order to find the relevant row in predicted_data where the look up latency corresponds to the actual latency. I then use this to created an amalgamated data set, full_set. I figured this would be really simple, but the find function keeps failing by throwing up an empty matrix when looking for an actual latency that I know is in predicted_data(:,1) (as I've double-checked during debugging). Moreover, if I replace find with a for loop to do the same job, I get a similar error. It doesn't appear to be systematic - using different participant data sets throws it up in different places. Furthermore, during debugging mode, if I use find to try and find a hard-coded value of actual_latency, it doesn't always work. Sometimes yes, sometimes no. I'm really scratching my head over this, so if anyone has any ideas about what might be going on, I'd be really grateful.

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• g-wan - reproducing the performance claims

  - by user2603628

  Using gwan_linux64-bit.tar.bz2 under Ubuntu 12.04 LTS unpacking and running gwan then pointing wrk at it (using a null file null.html) wrk --timeout 10 -t 2 -c 100 -d20s http://127.0.0.1:8080/null.html Running 20s test @ http://127.0.0.1:8080/null.html 2 threads and 100 connections Thread Stats Avg Stdev Max +/- Stdev Latency 11.65s 5.10s 13.89s 83.91% Req/Sec 3.33k 3.65k 12.33k 75.19% 125067 requests in 20.01s, 32.08MB read Socket errors: connect 0, read 37, write 0, timeout 49 Requests/sec: 6251.46 Transfer/sec: 1.60MB .. very poor performance, in fact there seems to be some kind of huge latency issue. During the test gwan is 200% busy and wrk is 67% busy. Pointing at nginx, wrk is 200% busy and nginx is 45% busy: wrk --timeout 10 -t 2 -c 100 -d20s http://127.0.0.1/null.html Thread Stats Avg Stdev Max +/- Stdev Latency 371.81us 134.05us 24.04ms 91.26% Req/Sec 72.75k 7.38k 109.22k 68.21% 2740883 requests in 20.00s, 540.95MB read Requests/sec: 137046.70 Transfer/sec: 27.05MB Pointing weighttpd at nginx gives even faster results: /usr/local/bin/weighttp -k -n 2000000 -c 500 -t 3 http://127.0.0.1/null.html weighttp - a lightweight and simple webserver benchmarking tool starting benchmark... spawning thread #1: 167 concurrent requests, 666667 total requests spawning thread #2: 167 concurrent requests, 666667 total requests spawning thread #3: 166 concurrent requests, 666666 total requests progress: 9% done progress: 19% done progress: 29% done progress: 39% done progress: 49% done progress: 59% done progress: 69% done progress: 79% done progress: 89% done progress: 99% done finished in 7 sec, 13 millisec and 293 microsec, 285172 req/s, 57633 kbyte/s requests: 2000000 total, 2000000 started, 2000000 done, 2000000 succeeded, 0 failed, 0 errored status codes: 2000000 2xx, 0 3xx, 0 4xx, 0 5xx traffic: 413901205 bytes total, 413901205 bytes http, 0 bytes data The server is a virtual 8 core dedicated server (bare metal), under KVM Where do I start looking to identify the problem gwan is having on this platform ? I have tested lighttpd, nginx and node.js on this same OS, and the results are all as one would expect. The server has been tuned in the usual way with expanded ephemeral ports, increased ulimits, adjusted time wait recycling etc.

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• Problem using find function in Matlab

  - by Peter Etchells

  Hi all, I have two arrays of data that I'm trying to amalgamate. One contains actual latencies from an experiment in the first column (e.g. 0.345, 0.455... never more than 3 decimal places), along with other data from that experiment. The other contains what is effectively a 'look up' list of latencies ranging from 0.001 to 0.500 in 0.001 increments, along with other pieces of data. Both data sets are X-by-Y doubles. What I'm trying to do is something like... for i = 1:length(actual_latency) row = find(predicted_data(:,1) == actual_latency(i) full_set(i,1:4) = [actual_latency(i) other_info(i) predicted_info(row,2)... predicted_info(row,3)]; end ...in order to find the relevant row in predicted_data where the look up latency corresponds to the actual latency. I then use this to created an amalgamated data set, full_set. I figured this would be really simple, but the find function keeps failing by throwing up an empty matrix when looking for an actual latency that I know is in predicted_data(:,1) (as I've double-checked during debugging). Moreover, if I replace find with a for loop to do the same job, I get a similar error. It doesn't appear to be systematic - using different participant data sets throws it up in different places. Furthermore, during debugging mode, if I use find to try and find a hard-coded value of actual_latency, it doesn't always work. Sometimes yes, sometimes no. I'm really scratching my head over this, so if anyone has any ideas about what might be going on, I'd be really grateful.

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• How to set 2 conditions / criterias for VLOOKUP / LOOKUP / etc in OpenOffice Calc (or Excel)

  - by MestreLion

  I have this spreadsheet that started as a silly aid for a game (Mafia Wars 2), but grew into a tricky spreadsheet question. In the game your character have 9 "slots" for weapons and armors, 1 for each "type": Light Weapon, Heavy Weapon, Body Armor, Head Armor, etc. So I made a list of all weapons and armors available in the game, 1 item per row. Example: SHOP ITEM TYPE ITEM NAME ATK DEF PRICE EQUIPPED? Marketplace Weapon Light Konrad Knife 16 5 5.500 Marketplace Weapon Light Ice Queen 19 6 8.200 Marketplace Armor Body Up Layered Polym 0 31 8.600 Marketplace Armor Body Up Full Shield 7 42 17.650 Marketplace Weapon Heavy Konrad Bullpup 53 25 24.500 Marketplace Weapon Heavy Full Moon Blow 73 12 24.500 x Marketplace Armor Body Low Knee Pads 17 26 14.200 x Marketplace Armor Body Low Army Boots 15 55 24.500 Bone Yard Weapon Light Bone Launcher 41 2 9.400 x Neon Strip Vehicle Ground Supercharged 41 34 24.500 Dead End Weapon Heavy Sharp Sickle 21 5 24.500 Dead End Armor Body Low Unholy Boots 5 36 15.000 Dead End Armor Head Hockey Mask 5 18 15.900 x Last columns is an indication of the items i have already bought and equipped (marked with "x"). What I need is a formula that, for each "slot" (item type), returns info related to the item of that kind that I am using. That would be: ITEM TYPE SHOP NAME ITEM NAME ATK DEF PRICE Weapon Light Bone Yard Bone Launcher 41 2 9.400 Weapon Heavy Marketplace Full Moon Blow 73 12 24.500 Weapon Special -- -- -- -- -- Armor Body Up -- -- -- -- -- Armor Body Low Marketplace Knee Pads 17 26 14.200 Armor Head Dead End Hockey Mask 5 18 15.900 Vehicle Ground -- -- -- -- -- Vehicle Water -- -- -- -- -- Vehicle Air -- -- -- -- -- The item types are fixed, so they can be hard coded. Each row for an item type. So, for 1st result line, it would return data from the row where both 2nd column is "Weapon Light" and last column is "x". Basically I need a LOOKUP (or VLOOKUP, or anything else) that uses 2 criteria to find a given row, the item type and the X marker. Question is: HOW? I am using OpenOffice Calc 3.2.1, but since it shares so many functions with MS Excel, answers for Excel are also fine (as long as it only uses regular formulas, no VBScript or Macros or VBA etc) Last but not least, suggestions / solutions for rearranging the data so it makes this problem easier to solve are also welcome. Thanks!

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• Satellite data in Russia?

  - by Eddy

  Anyone familiar with options for transmitting data in Russia? I'd be interested in hearing about low-speed packet data and faster. Not really looking at VSAT initially as I'd like to keep the power requirements low unless we find no other options.

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• How to stop switchable graphics from switching to high-power GPU when charging the laptop?

  - by Saifallah

  I've an Acer laptop with Windows 7 64 bit and an ATI Radeon HD 6550M Graphics card. Whenever I connect the power to charge the battery it automatically switches to the high-power GPU (ATI) instead of the low-power (Intel) GPU. There's an option in the bios to stop such thing but it makes the GPU runs always on high-power and I can't switch to the low-power GPU. How can I prevent the switchable graphics from automatically using the high-power GPU when charging?

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• Linux server very slow after IP change and synflood attack

  - by Johannes Ruof

  our server experienced a synflood attack and we used the csf firewall synflood settings to block it. Our server administrators also changed the IP of the server to a new one and blackholed the old IP. The attack went over and I changed the synflood settings back. However the server is still very slow, with a very low CPU usage and very low traffic on the website. Does anybody have an idea what might be causing this? The server is a CENTOS 6.4 x86_64 Thanks in advance, J. Ruof

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• How can order of IP addresses issued be controlled?

  - by warren

  Every home router I've setup/used issues addresses from low to high. However, dhcpd from the Internet Systems Consortium seems to issue addresses in reverse order - ie, high to low. Is there a way to change this so that addresses are issued starting at the bottom of the range, and progress higher?

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