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  • EM CLI, diving in and beyond!

    - by Maureen Byrne
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Doing more in less time… Isn’t that what we all strive to do? With this in mind, I put together two screen watches on Oracle Enterprise Manager 12c command line interface, or EM CLI as it is also known. There is a wealth of information on any topic that you choose to read about, from manual pages to coding documents…might I even say blog posts? In our busy lives it is so nice to just sit back with a short video, watch and learn enough to dive in. Doing more in less time, is the essence of EM CLI. It enables you to script fundamental and complex administrative tasks in an elegant way, thanks to the Jython scripting language. Repetitive tasks can be scripted and reused again and again. Sure, a Graphical User Interface provides a more intuitive step by step approach to tasks, and it provides a way of quickly becoming familiar with a product and its many features, and it is definitely the way to go when viewing performance data and historical trending…but for repetitive and complex tasks, scripting is the way to go! Lets us take the everyday task of creating an administrator. Using EM CLI in interactive mode the command could look like this.. emcli>create_user(name='jan.doe', type='EXTERNAL_USER') This command creates an administrator called jan.doe which is an externally authenticated user, possibly LDAP or SSO, defined by the EXTERNAL_USER tag. The create_user procedure takes many arguments; see the documentation for more information. Now, where EM CLI really shines and shows power is in creating multiple users. Regardless of the number, tens or thousands, the effort is the same. With the use of a standard programming construct, a loop, you can place your create_user() procedure within it. Using a loop allows you to iterate through a previously created list, creating new users until the list is complete. Using EM CLI in Script mode, your Jython loop would look something like this… for user in list_of_users:       create_user(name=user, expire=’true’, password=’welcome123’) This Jython code snippet iterates through a previously defined list of names, list_of_users, and iterates through the list, taking each name, user in this case, and creates an administrator sets the password to welcome123, but forces the user to reset it when they first login. This is only one of over four hundred procedures created to expose Oracle Enterprise Manager 12c functionality in a powerful and programmatic way. It is a few months since we released EM CLI with scripting option. We are seeing many users adapt to this fun and powerful way of using Oracle Enterprise Manager 12c. What are the first steps? Watch these screen watches, and dive in. The first screen watch steps you through where and how to download and install and how to run your first few commands. The Second screen watch steps you through a few scripts. Next time, I am going to show you the basic building blocks to writing a Jython script to perform Oracle Enterprise Manager 12c administrative tasks. Join this growing group of EM CLI users…. Dive in! Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • What developer conferences are you going to this year?

    - by mbcrump
    This short list is what I consider to be the “cream-of-the-crop” in developer conferences. This is also a list of the conferences that I plan on attending in 2011. If you feel your conference is just as good, then shoot me an email at [michael[at]michaelcrump[dot]net, and if possible I will check it out.   In-Person Event Las Vegas on April 18th-22nd, 2011 Redmond on October 17th-21st, 2011 Orlando on December 5th-9th, 2011 Visual Studio Live – I attended this event in November of last year and blogged about my experience. I am also planning on going back to the Orlando session in December of this year. So what did I like the most about this event? Being able to interact one-on-one with a majority of the speakers. If you read my blog post then you will see a list of the speakers that I met up with. I also made a lot of great connections with other professional developers all over the world. They are having an event in Las Vegas on April 18th-22nd. I noticed at this event that they have added a new track on mobile. Being a big fan of mobile, I feel that this is a great move. They also have a great selection for Silverlight Developers including Billy Hollis and Rocky Lhotka. For the full lineup of conference tracks, sessions and speakers visit http://bit.ly/VSLiveTrks. If you are interested in this then you can register here by February 16th. I must add that you can save $300 bucks by getting the early-bird special.   Virtual Conference SSWUG (DBTechCon) - holds the largest virtual conference in the information technology industry. It is also special to me because they selected a majority of my Silverlight content for the April conference. No traveling fees and all of the sessions are recorded so you can watch them on-demand for $189 bucks (early-bird special). For the entire speaker list then click here. The session list has also been published. If you are interested in this then you can register here.   In-Person Event Knoxville, TN on June 3rd/4th 2011. Codestock.org – If you live in the South then you have heard of CodeStock. To my knowledge, they have only had 3 events so far and they were a huge success. It was such a success that after the last event, everyone was telling me how good it was and how much they enjoyed it. They currently have a call for speakers going on right now, so if you have sessions then be sure to submit yours. So, what makes them stand out? Well for starters Michael Neal (organizer) developed an open API so conference attendees could build their own apps for the sessions. They also encouraged their speakers to go to other sessions instead of stay in a “speaker-room”. Another cool feature is that they are uploading videos from the conference so everyone can benefit. They are currently looking for sponsorship, so help out if you can.   In-Person Event Redmond, WA on October 28/29 2011 *NOT 100% SURE AT THIS POINT* PDC 11 – OK, so the logo should be pdc11 but its not out yet. This event is located on Microsoft’s campus in Redmond, WA. It is probably one of the most well known conferences for developers to attend. One of the big perks from this event is that you typically come away with free stuff. In 2010 they gave away Windows 7 Phones. I remember years earlier they gave away laptops. This of course isn’t the only reason to go, you may get to tour the Microsoft campus. Since pdc is a huge event, you can view all the events for free. Mike Taulty created a nice Silverlight application that consumes the OData feed. You can download it here. If everything goes as planned, I will be at all of these events. If you plan on going then send me a tweet and we will do lunch or dinner. I love meeting new developers and talking .net.  Subscribe to my feed

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  • Oracle NoSQL Database Exceeds 1 Million Mixed YCSB Ops/Sec

    - by Charles Lamb
    We ran a set of YCSB performance tests on Oracle NoSQL Database using SSD cards and Intel Xeon E5-2690 CPUs with the goal of achieving 1M mixed ops/sec on a 95% read / 5% update workload. We used the standard YCSB parameters: 13 byte keys and 1KB data size (1,102 bytes after serialization). The maximum database size was 2 billion records, or approximately 2 TB of data. We sized the shards to ensure that this was not an "in-memory" test (i.e. the data portion of the B-Trees did not fit into memory). All updates were durable and used the "simple majority" replica ack policy, effectively 'committing to the network'. All read operations used the Consistency.NONE_REQUIRED parameter allowing reads to be performed on any replica. In the past we have achieved 100K ops/sec using SSD cards on a single shard cluster (replication factor 3) so for this test we used 10 shards on 15 Storage Nodes with each SN carrying 2 Rep Nodes and each RN assigned to its own SSD card. After correcting a scaling problem in YCSB, we blew past the 1M ops/sec mark with 8 shards and proceeded to hit 1.2M ops/sec with 10 shards.  Hardware Configuration We used 15 servers, each configured with two 335 GB SSD cards. We did not have homogeneous CPUs across all 15 servers available to us so 12 of the 15 were Xeon E5-2690, 2.9 GHz, 2 sockets, 32 threads, 193 GB RAM, and the other 3 were Xeon E5-2680, 2.7 GHz, 2 sockets, 32 threads, 193 GB RAM.  There might have been some upside in having all 15 machines configured with the faster CPU, but since CPU was not the limiting factor we don't believe the improvement would be significant. The client machines were Xeon X5670, 2.93 GHz, 2 sockets, 24 threads, 96 GB RAM. Although the clients had 96 GB of RAM, neither the NoSQL Database or YCSB clients require anywhere near that amount of memory and the test could have just easily been run with much less. Networking was all 10GigE. YCSB Scaling Problem We made three modifications to the YCSB benchmark. The first was to allow the test to accommodate more than 2 billion records (effectively int's vs long's). To keep the key size constant, we changed the code to use base 32 for the user ids. The second change involved to the way we run the YCSB client in order to make the test itself horizontally scalable.The basic problem has to do with the way the YCSB test creates its Zipfian distribution of keys which is intended to model "real" loads by generating clusters of key collisions. Unfortunately, the percentage of collisions on the most contentious keys remains the same even as the number of keys in the database increases. As we scale up the load, the number of collisions on those keys increases as well, eventually exceeding the capacity of the single server used for a given key.This is not a workload that is realistic or amenable to horizontal scaling. YCSB does provide alternate key distribution algorithms so this is not a shortcoming of YCSB in general. We decided that a better model would be for the key collisions to be limited to a given YCSB client process. That way, as additional YCSB client processes (i.e. additional load) are added, they each maintain the same number of collisions they encounter themselves, but do not increase the number of collisions on a single key in the entire store. We added client processes proportionally to the number of records in the database (and therefore the number of shards). This change to the use of YCSB better models a use case where new groups of users are likely to access either just their own entries, or entries within their own subgroups, rather than all users showing the same interest in a single global collection of keys. If an application finds every user having the same likelihood of wanting to modify a single global key, that application has no real hope of getting horizontal scaling. Finally, we used read/modify/write (also known as "Compare And Set") style updates during the mixed phase. This uses versioned operations to make sure that no updates are lost. This mode of operation provides better application behavior than the way we have typically run YCSB in the past, and is only practical at scale because we eliminated the shared key collision hotspots.It is also a more realistic testing scenario. To reiterate, all updates used a simple majority replica ack policy making them durable. Scalability Results In the table below, the "KVS Size" column is the number of records with the number of shards and the replication factor. Hence, the first row indicates 400m total records in the NoSQL Database (KV Store), 2 shards, and a replication factor of 3. The "Clients" column indicates the number of YCSB client processes. "Threads" is the number of threads per process with the total number of threads. Hence, 90 threads per YCSB process for a total of 360 threads. The client processes were distributed across 10 client machines. Shards KVS Size Clients Mixed (records) Threads OverallThroughput(ops/sec) Read Latencyav/95%/99%(ms) Write Latencyav/95%/99%(ms) 2 400m(2x3) 4 90(360) 302,152 0.76/1/3 3.08/8/35 4 800m(4x3) 8 90(720) 558,569 0.79/1/4 3.82/16/45 8 1600m(8x3) 16 90(1440) 1,028,868 0.85/2/5 4.29/21/51 10 2000m(10x3) 20 90(1800) 1,244,550 0.88/2/6 4.47/23/53

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  • Webcor Builders Coordinates Construction Schedules and Mitigates Potential Delays More Efficiently with Integrated Project Management

    - by Sylvie MacKenzie, PMP
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} With more than 40 years of commercial construction experience, Webcor Builders is a leading builder of distinguished, high-profile projects, including high-rise condominiums and hotels, laboratories, healthcare centers, and public works projects. Webcor is also known for its award-winning concrete, interior construction, historic restoration, and seismic renovation work. The company has completed more than 50 million square feet of projects to date. Considering the variety and complexity of the construction projects Webcor undertakes, an integrated project management solution is critical to ensuring optimal efficiency and completing client projects on time and on budget. The company previously used a number of scheduling systems for its various building projects. These packages provided different levels of schedule detail and required schedulers, engineers, and other employees to learn multiple systems. From an IT cost and complexity perspective, the company had to manage multiple scheduling systems and pay for multiple sets of licenses. The company looked to standardize on an enterprise project management system, and selected Oracle’s Primavera P6 Enterprise Project Portfolio Management. Webcor uses the solution’s advanced capabilities to schedule complex projects, analyze delays, model and propose multiple scenarios to demonstrate and mitigate delays and cost overruns, and process that information efficiently to deliver the scheduling precision that public and private projects require. In fact, the solution was instrumental in helping the company’s expansion into public sector projects during the recent economic downturn, and with Primavera P6 in place, it can deliver the precise schedule reporting required for large public projects. With Primavera P6 in place, the company could deliver the precise scheduling and milestone reporting capabilities required for large public projects. The solution is in managing the high-profile University of California – Berkeley Memorial Stadium project. Webcor was hired as construction manager and general contractor for the stadium renovation project, which is a fast-paced project located near the seismically active Hayward Fault Zone. Due to the University of California’s football schedule, meeting the Universities deadline for the coming season placed Webcor in a situation where risk awareness and early warnings of issues would be paramount. Webcor and the extended project team needed a solution that could instantly analyze alternate scenarios to mitigate potential delays; Primavera would deliver those answers.The team would also need to enable multiple stakeholders to use an internet-based platform to access the schedule from various locations, and model complicated sequencing requirements where swift decisions would be made to keep the project on track. The schedule is an integral part of Webcor’s construction management process for the stadium project. Rather than providing the client with the industry-standard monthly update, Webcor updates the critical path method (CPM) schedule on a weekly basis. The project team also reviews the schedule and updates weekly to confirm that progress and forecasted performance are accurate. Hired by the University for their ability to deliver in high risk environments The Webcor team was hit recently with a design supplement that could have added up to 70 days to the project. Using Oracle Primavera P6 the team sprung into action analyzing multiple “what if” scenarios to review mitigation means and methods.  Determined to make sure the Bears could take the field in the coming season the project team nearly eliminated the impact with their creative analysis in working the schedule. The total time from the issuance of the final design supplement to an agreed mitigation response was less than one week; leveraging the Oracle Primavera solution Webcor was able to deliver superior customer value With the ability to efficiently manage projects and schedules, Webcor can ensure it completes its projects on time and on budget, as well as inform clients about what changes to plans will mean in terms of delays and additional costs. Read the complete customer case study at :  http://www.oracle.com/us/corporate/customers/customersearch/webcor-builders-1-primavera-ss-1639886.html

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  • What Counts for a DBA: Humility

    - by drsql
    In football (the American sort, naturally,) there are a select group of players who really hope to never have their names called during the game. They are members of the offensive line, and their job is to protect other players so they can deliver the ball to the goal to score points. When you do hear their name called, it is usually because they made a mistake and the player that they were supposed to protect ended up flat on his back admiring the clouds in the sky instead of advancing towards the goal to scoring point. Even on the rare occasion their name is called for a good reason, it is usually because they were making up for a teammate who had made a mistake and they covered up for them. The role of offensive lineman is a very good analogy for the role of the admin DBA. As a DBA, you are called on to be barely visible and rarely heard, protecting the company data assets tenaciously, even though the enemies to our craft surround us on all sides:. Developers: Cries of ‘foul!’ often ensue when the DBA says that they want data integrity to be stringently enforced and that documentation is needed so they can support systems, mostly because every error occurrence in the enterprise will be initially blamed on the database and fall to the DBA to troubleshoot. Insisting too loudly may bring those cries of ‘foul’ that somewhat remind you of when your 2 year old daughter didn't want to go to bed. The result of this petulance is that the next "enemy" gets involved. Managers: The concerns that motivate DBAs to argue will not excite the kind of manager who gets his technical knowledge from a glossy magazine filled with buzzwords, charts, and pretty pictures. However, the other programmers in the organization will tickle the buzzword void with a stream of new-sounding ideas and technologies constantly, along with warnings that if we did care about data integrity and document things, the budget would explode! In contrast, the arguments for integrity of data and supportability tend to be about as exciting as watching grass grow, and far too many manager types seem to prefer to smoke it than watch it. Packaged Applications: The DBA is rarely given a chance to review a new application that is being demonstrated for the enterprise, and rarer still is the DBA that gets a veto of an application because the database it uses has clearly been created by an architect that won't read a data modeling book because he is already married. More often than not this leads to hours of work for the DBA trying to performance-tune a database with a menagerie of rules that must be followed to stay within the  application support agreement, such as no changing indexes on a third party schema even though there are 10 billion rows instead of the 10 thousand when the system was last optimized. Hardware Failures: Physical disks, networking devices, memory, and backup devices all come with a measure known as ‘mean time before failure’ and it is never listed in centuries or eons. More like years, and the term ‘mean’ indicates that half of the devices are expected to fail before that, which by my calendar means any hour of any day that it wants to fail it will. But the DBA sucks it up and does the task at hand with a humility that makes them nearly invisible to all but the most observant person in the organization. The best DBAs I know are so proactive in their relentless pursuit of perfection that they detect many of the bugs (which they seldom caused) in the system well before they become a problem. In the end the DBA gets noticed for one of same two reasons as the offensive lineman. You make a mistake, like dropping a critical production database that had never been backed up; or when a system crashes for any reason whatsoever and they are on the spot with troubleshooting and system restoration plans that have been well thought out, tested, and tested again. Not because there is any glory in it, but because it is what they do.   Note: The characteristics of the professions referred to in this blog are meant to be overstated stereotypes for humorous effect, and even some DBAs aren't quite this perfect. If you are reading this far and haven’t hand written a 10 page flaming comment about how you are a _______ and you aren’t like this, that is awesome. Not every situation applies to everyone, but if you have never worked with a bad packaged app, a magazine trained manager, programmers that aren’t team players, or hardware that occasionally failed, relax and go have a unicorn sandwich before you wake up.

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  • CPU Usage in Very Large Coherence Clusters

    - by jpurdy
    When sizing Coherence installations, one of the complicating factors is that these installations (by their very nature) tend to be application-specific, with some being large, memory-intensive caches, with others acting as I/O-intensive transaction-processing platforms, and still others performing CPU-intensive calculations across the data grid. Regardless of the primary resource requirements, Coherence sizing calculations are inherently empirical, in that there are so many permutations that a simple spreadsheet approach to sizing is rarely optimal (though it can provide a good starting estimate). So we typically recommend measuring actual resource usage (primarily CPU cycles, network bandwidth and memory) at a given load, and then extrapolating from those measurements. Of course there may be multiple types of load, and these may have varying degrees of correlation -- for example, an increased request rate may drive up the number of objects "pinned" in memory at any point, but the increase may be less than linear if those objects are naturally shared by concurrent requests. But for most reasonably-designed applications, a linear resource model will be reasonably accurate for most levels of scale. However, at extreme scale, sizing becomes a bit more complicated as certain cluster management operations -- while very infrequent -- become increasingly critical. This is because certain operations do not naturally tend to scale out. In a small cluster, sizing is primarily driven by the request rate, required cache size, or other application-driven metrics. In larger clusters (e.g. those with hundreds of cluster members), certain infrastructure tasks become intensive, in particular those related to members joining and leaving the cluster, such as introducing new cluster members to the rest of the cluster, or publishing the location of partitions during rebalancing. These tasks have a strong tendency to require all updates to be routed via a single member for the sake of cluster stability and data integrity. Fortunately that member is dynamically assigned in Coherence, so it is not a single point of failure, but it may still become a single point of bottleneck (until the cluster finishes its reconfiguration, at which point this member will have a similar load to the rest of the members). The most common cause of scaling issues in large clusters is disabling multicast (by configuring well-known addresses, aka WKA). This obviously impacts network usage, but it also has a large impact on CPU usage, primarily since the senior member must directly communicate certain messages with every other cluster member, and this communication requires significant CPU time. In particular, the need to notify the rest of the cluster about membership changes and corresponding partition reassignments adds stress to the senior member. Given that portions of the network stack may tend to be single-threaded (both in Coherence and the underlying OS), this may be even more problematic on servers with poor single-threaded performance. As a result of this, some extremely large clusters may be configured with a smaller number of partitions than ideal. This results in the size of each partition being increased. When a cache server fails, the other servers will use their fractional backups to recover the state of that server (and take over responsibility for their backed-up portion of that state). The finest granularity of this recovery is a single partition, and the single service thread can not accept new requests during this recovery. Ordinarily, recovery is practically instantaneous (it is roughly equivalent to the time required to iterate over a set of backup backing map entries and move them to the primary backing map in the same JVM). But certain factors can increase this duration drastically (to several seconds): large partitions, sufficiently slow single-threaded CPU performance, many or expensive indexes to rebuild, etc. The solution of course is to mitigate each of those factors but in many cases this may be challenging. Larger clusters also lead to the temptation to place more load on the available hardware resources, spreading CPU resources thin. As an example, while we've long been aware of how garbage collection can cause significant pauses, it usually isn't viewed as a major consumer of CPU (in terms of overall system throughput). Typically, the use of a concurrent collector allows greater responsiveness by minimizing pause times, at the cost of reducing system throughput. However, at a recent engagement, we were forced to turn off the concurrent collector and use a traditional parallel "stop the world" collector to reduce CPU usage to an acceptable level. In summary, there are some less obvious factors that may result in excessive CPU consumption in a larger cluster, so it is even more critical to test at full scale, even though allocating sufficient hardware may often be much more difficult for these large clusters.

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  • Performance triage

    - by Dave
    Folks often ask me how to approach a suspected performance issue. My personal strategy is informed by the fact that I work on concurrency issues. (When you have a hammer everything looks like a nail, but I'll try to keep this general). A good starting point is to ask yourself if the observed performance matches your expectations. Expectations might be derived from known system performance limits, prototypes, and other software or environments that are comparable to your particular system-under-test. Some simple comparisons and microbenchmarks can be useful at this stage. It's also useful to write some very simple programs to validate some of the reported or expected system limits. Can that disk controller really tolerate and sustain 500 reads per second? To reduce the number of confounding factors it's better to try to answer that question with a very simple targeted program. And finally, nothing beats having familiarity with the technologies that underlying your particular layer. On the topic of confounding factors, as our technology stacks become deeper and less transparent, we often find our own technology working against us in some unexpected way to choke performance rather than simply running into some fundamental system limit. A good example is the warm-up time needed by just-in-time compilers in Java Virtual Machines. I won't delve too far into that particular hole except to say that it's rare to find good benchmarks and methodology for java code. Another example is power management on x86. Power management is great, but it can take a while for the CPUs to throttle up from low(er) frequencies to full throttle. And while I love "turbo" mode, it makes benchmarking applications with multiple threads a chore as you have to remember to turn it off and then back on otherwise short single-threaded runs may look abnormally fast compared to runs with higher thread counts. In general for performance characterization I disable turbo mode and fix the power governor at "performance" state. Another source of complexity is the scheduler, which I've discussed in prior blog entries. Lets say I have a running application and I want to better understand its behavior and performance. We'll presume it's warmed up, is under load, and is an execution mode representative of what we think the norm would be. It should be in steady-state, if a steady-state mode even exists. On Solaris the very first thing I'll do is take a set of "pstack" samples. Pstack briefly stops the process and walks each of the stacks, reporting symbolic information (if available) for each frame. For Java, pstack has been augmented to understand java frames, and even report inlining. A few pstack samples can provide powerful insight into what's actually going on inside the program. You'll be able to see calling patterns, which threads are blocked on what system calls or synchronization constructs, memory allocation, etc. If your code is CPU-bound then you'll get a good sense where the cycles are being spent. (I should caution that normal C/C++ inlining can diffuse an otherwise "hot" method into other methods. This is a rare instance where pstack sampling might not immediately point to the key problem). At this point you'll need to reconcile what you're seeing with pstack and your mental model of what you think the program should be doing. They're often rather different. And generally if there's a key performance issue, you'll spot it with a moderate number of samples. I'll also use OS-level observability tools to lock for the existence of bottlenecks where threads contend for locks; other situations where threads are blocked; and the distribution of threads over the system. On Solaris some good tools are mpstat and too a lesser degree, vmstat. Try running "mpstat -a 5" in one window while the application program runs concurrently. One key measure is the voluntary context switch rate "vctx" or "csw" which reflects threads descheduling themselves. It's also good to look at the user; system; and idle CPU percentages. This can give a broad but useful understanding if your threads are mostly parked or mostly running. For instance if your program makes heavy use of malloc/free, then it might be the case you're contending on the central malloc lock in the default allocator. In that case you'd see malloc calling lock in the stack traces, observe a high csw/vctx rate as threads block for the malloc lock, and your "usr" time would be less than expected. Solaris dtrace is a wonderful and invaluable performance tool as well, but in a sense you have to frame and articulate a meaningful and specific question to get a useful answer, so I tend not to use it for first-order screening of problems. It's also most effective for OS and software-level performance issues as opposed to HW-level issues. For that reason I recommend mpstat & pstack as my the 1st step in performance triage. If some other OS-level issue is evident then it's good to switch to dtrace to drill more deeply into the problem. Only after I've ruled out OS-level issues do I switch to using hardware performance counters to look for architectural impediments.

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  • Clone a VirtualBox Machine

    I just installed VirtualBox, which I want to try out based on recommendations from peers for running a server from within my Windows 7 x64 OS.  Ive never used VirtualBox, so Im certainly no expert at it, but I did want to share my experience with it thus far.  Specifically, my intention is to create a couple of virtual machines.  One I intend to use as a build server, for which a virtual machine makes sense because I can easily move it around as needed if there are hardware issues (its worth noting my need for setting up a build server at the moment is a result of a disk failure on the old build server).  The other VM I want to set up will act as a proxy server for the issue tracking system were using at Code Project, Axosoft OnTime.  They have a Remote Server application for this purpose, and since the OnTime install is 300 miles away from my location, the Remote Server should speed up my use of the OnTime client by limiting the chattiness with the database (at least, thats the hope). So, I need two VMs, and Im lazy.  I dont want to have to install the OS and such twice.  No problem, it should be simple to clone a virtualbox machine, or clone a virtualbox hard drive, right?  Well unfortunately, if you look at the UI for VirtualBox, theres no such command.  Youre left wondering How do I clone a VirtualBox machine? or the slightly related How do I clone a VirtualBox hard drive? If youve used VirtualPC, then you know that its actually pretty easy to copy and move around those VMs.  Not quite so easy with VirtualBox.  Finding the files is easy, theyre located in your user folder within the .VirtualBox folder (possibly within a HardDisks folder).  The disks have a .vdi extension and will be pretty large if youve installed anything.  The one shown here has just Windows Server 2008 R2 installed on it nothing else. If you copy the .vdi file and rename it, you can use the Virtual Media Manager to view it and you can create a new machine and choose the new drive to attach to.  Unfortunately, if you simply make a copy of the drive, this wont work and youll get an error that says something to the effect of: Cannot register the hard disk PATH with UUID {id goes here} because a hard disk PATH2 with UUID {same id goes here} already exists in the media registry (PATH to XML file). There are command line tools you can use to do this in a way that avoids this error.  Specifically, the c:\Program File\Sun\VirtualBox\VBoxManage.exe program is used for all command line access to VirtualBox, and to copy a virtual disk (.vdi file) you would call something like this: VBoxManage clonehd Disk1.vdi Disk1_Copy.vdi However, in my case this didnt work.  I got basically the same error I showed above, along with some debug information for line 628 of VBoxManageDisk.cpp.  As my main task was not to debug the C++ code used to write VirtualBox, I continued looking for a simple way to clone a virtual drive.  I found it in this blog post. The Secret setvdiuuid Command VBoxManage has a whole bunch of commands you can use with it just pass it /? to see the list.  However, it also has a special command called internalcommands that opens up access to even more commands.  The one thats interesting for us here is the setvdiuuid command.  By calling this command and passing in the file path to your vdi file, it will reset the UUID to a new (random, apparently) UUID.  This then allows the virtual media manager to cope with the file, and lets you set up new machines that reference the newly UUIDd virtual drive.  The full command line would be: VBoxManage internalcommands setvdiuuid MyCopy.vdi The following screenshot shows the error when trying clonehd as well as the successful use of setvdiuuid. Summary Now that I can clone machines easily, its a simple matter to set up base builds of any OS I might need, and then fork from there as needed.  Hopefully the GUI for VirtualBox will be improved to include better support for copying machines/disks, as this is Im sure a very common scenario. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Navigate Quickly with JustCode and Ctrl+Click

    Ctrl + Click is a widely used shortcut for Go To Definition in many development environments but not in Visual Studio. We, the JustCode team, find it really useful so we added it to Visual Studio. But we didn't stop there - we improved it even further. Read on to find the details. With JustCode you get an enhanced Go To Definition. By default you can execute it in the Visual Studio editor using one of the following shortcuts: Middle Click, Ctrl+Left Click, F12, Ctrl+Enter, Ctrl+B. The first usage of this feature is not much different from the default Visual Studio Go To Definition command use it where a member, type, method, property, etc is used to navigate to the definition of that item. For example, if you have this method:         public void Start()         {             lion = new Lion();             lion.Roar();         } If you hold Ctrl and click on the usage of the lion you will go to the lion member definition. If you hold Ctrl and click on the Lion you will go to the Lion class definition. What we added is the ability to easily find all the usages of the item you just navigated to. For example:     public class Lion     {         public void Roar()         {             Console.WriteLine("Rhaaaar");         }     }   If you hold Ctrl and click on the Lion definition you will see all the usages of the Lion type; if you click on the Roar method definition you will see all the usages of the Roar method: And if there is only one usage you will get automatically to that usage. In the examples I use C#, but it works also in VB.NET, JavaScript, ASP.NET and XAML. Why we like this feature? Let me first start with how the Ctrl+Click (or Go To Definition command) is used. We noticed that developers use it especially in what we call "code browsing sessions". In simple words this is when you browse around the code looking for a bug, just reading the code or searching for something. Sounds familiar? In our experience when you go to the definition of some item you often want to know more about it and the first thing you need is to find its usages. With JustCode this is just one click away. Why Ctrl+Click/Middle Click over F12/Ctrl+Enter/Ctrl+B? Actually you can use all of them. But during these "code browsing sessions" we noticed that most developers use the mouse. So the mouse is already in use and pressing Ctrl+Click (or the Middle Click) is so natural. During heavy coding sessions or if you are a keyboard type developer F12 (or any of the other keyboard shortcuts) is the key. We really use heavily this feature not only in our team but in the whole company. It saves us a bit of time many times a day. And it adds up. We hope you will like it too. Your feedback is more than welcome for us. P.S. If you dont want JustCode to capture the Ctrl+Click and the Middle Click in the editor, you can change that in JustCode->Options->General in the Navigation group. Keyboard shortcuts can be reassigned using the Visual Studio keyboard shortcuts editor.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • What Counts for A DBA - Logic

    - by drsql
    "There are 10 kinds of people in the world. Those who will always wonder why there are only two items in my list and those who will figured it out the first time they saw this very old joke."  Those readers who will give up immediately and get frustrated with me for not explaining it to them are not likely going to be great technical professionals of any sort, much less a programmer or administrator who will be constantly dealing with the common failures that make up a DBA's day.  Many of these people will stare at this like a dog staring at a traffic signal and still have no more idea of how to decipher the riddle. Without explanation they will give up, call the joke "stupid" and, feeling quite superior, walk away indignantly to their job likely flipping patties of meat-by-product. As a data professional or any programmer who has strayed  to this very data-oriented blog, you would, if you are worth your weight in air, either have recognized immediately what was going on, or felt a bit ignorant.  Your friends are chuckling over the joke, but why is it funny? Unfortunately you left your smartphone at home on the dresser because you were up late last night programming and were running late to work (again), so you will either have to fake a laugh or figure it out.  Digging through the joke, you figure out that the word "two" is the most important part, since initially the joke mentioned 10. Hmm, why did they spell out two, but not ten? Maybe 10 could be interpreted a different way?  As a DBA, this sort of logic comes into play every day, and sometimes it doesn't involve nerdy riddles or Star Wars folklore.  When you turn on your computer and get the dreaded blue screen of death, you don't immediately cry to the help desk and sit on your thumbs and whine about not being able to work. Do that and your co-workers will question your nerd-hood; I know I certainly would. You figure out the problem, and when you have it narrowed down, you call the help desk and tell them what the problem is, usually having to explain that yes, you did in fact try to reboot before calling.  Of course, sometimes humility does come in to play when you reach the end of your abilities, but the ‘end of abilities’ is not something any of us recognize readily. It is handy to have the ability to use logic to solve uncommon problems: It becomes especially useful when you are trying to solve a data-related problem such as a query performance issue, and the way that you approach things will tell your coworkers a great deal about your abilities.  The novice is likely to immediately take the approach of  trying to add more indexes or blaming the hardware. As you become more and more experienced, it becomes increasingly obvious that performance issues are a very complex topic. A query may be slow for a myriad of reasons, from concurrency issues, a poor query plan because of a parameter value (like parameter sniffing,) poor coding standards, or just because it is a complex query that is going to be slow sometimes. Some queries that you will deal with may have twenty joins and hundreds of search criteria, and it can take a lot of thought to determine what is going on.  You can usually figure out the problem to almost any query by using basic knowledge of how joins and queries work, together with the help of such things as the query plan, profiler or monitoring tools.  It is not unlikely that it can take a full day’s work to understand some queries, breaking them down into smaller queries to find a very tiny problem. Not every time will you actually find the problem, and it is part of the process to occasionally admit that the problem is random, and everything works fine now.  Sometimes, it is necessary to realize that a problem is outside of your current knowledge, and admit temporary defeat: You can, at least, narrow down the source of the problem by looking logically at all of the possible solutions. By doing this, you can satisfy your curiosity and learn more about what the actual problem was. For example, in the joke, had you never been exposed to the concept of binary numbers, there is no way you could have known that binary - 10 = decimal - 2, but you could have logically come to the conclusion that 10 must not mean ten in the context of the joke, and at that point you are that much closer to getting the joke and at least won't feel so ignorant.

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  • Pirates, Treasure Chests and Architectural Mapping

    Pirate 1: Why do pirates create treasure maps? Pirate 2: I do not know.Pirate 1: So they can find their gold. Yes, that was a bad joke, but it does illustrate a point. Pirates are known for drawing treasure maps to their most prized possession. These documents detail the decisions pirates made in order to hide and find their chests of gold. The map allows them to trace the steps they took originally to hide their treasure so that they may return. As software engineers, programmers, and architects we need to treat software implementations much like our treasure chest. Why is software like a treasure chest? It cost money, time,  and resources to develop (Usually) It can make or save money, time, and resources (Hopefully) If we operate under the assumption that software is like a treasure chest then wouldn’t make sense to document the steps, rationale, concerns, and decisions about how it was designed? Pirates are notorious for documenting where they hide their treasure.  Shouldn’t we as creators of software do the same? By documenting our design decisions and rationale behind them will help others be able to understand and maintain implemented systems. This can only be done if the design decisions are correctly mapped to its corresponding implementation. This allows for architectural decisions to be traced from the conceptual model, architectural design and finally to the implementation. Mapping gives software professional a method to trace the reason why specific areas of code were developed verses other options. Just like the pirates we need to able to trace our steps from the start of a project to its implementation,  so that we will understand why specific choices were chosen. The traceability of a software implementation that actually maps back to its originating design decisions is invaluable for ensuring that architectural drifting and erosion does not take place. The drifting and erosion is prevented by allowing others to understand the rational of why an implementation was created in a specific manor or methodology The process of mapping distinct design concerns/decisions to the location of its implemented is called traceability. In this context traceability is defined as method for connecting distinctive software artifacts. This process allows architectural design models and decisions to be directly connected with its physical implementation. The process of mapping architectural design concerns to a software implementation can be very complex. However, most design decision can be placed in  a few generalized categories. Commonly Mapped Design Decisions Design Rationale Components and Connectors Interfaces Behaviors/Properties Design rational is one of the hardest categories to map directly to an implementation. Typically this rational is mapped or document in code via comments. These comments consist of general design decisions and reasoning because they do not directly refer to a specific part of an application. They typically focus more on the higher level concerns. Components and connectors can directly be mapped to architectural concerns. Typically concerns subdivide an application in to distinct functional areas. These functional areas then can map directly back to their originating concerns.Interfaces can be mapped back to design concerns in one of two ways. Interfaces that pertain to specific function definitions can be directly mapped back to its originating concern(s). However, more complicated interfaces require additional analysis to ensure that the proper mappings are created. Depending on the complexity some Behaviors\Properties can be translated directly into a generic implementation structure that is ready for business logic. In addition, some behaviors can be translated directly in to an actual implementation depending on the complexity and architectural tools used. Mapping design concerns to an implementation is a lot of work to maintain, but is doable. In order to ensure that concerns are mapped correctly and that an implementation correctly reflects its design concerns then one of two standard approaches are usually used. All Changes Come From ArchitectureBy forcing all application changes to come through the architectural model prior to implementation then the existing mappings will be used to locate where in the implementation changes need to occur. Allow Changes From Implementation Or Architecture By allowing changes to come from the implementation and/or the architecture then the other area must be kept in sync. This methodology is more complex compared to the previous approach.  One reason to justify the added complexity for an application is due to the fact that this approach tends to detect and prevent architectural drift and erosion. Additionally, this approach is usually maintained via software because of the complexity. Reference:Taylor, R. N., Medvidovic, N., & Dashofy, E. M. (2009). Software architecture: Foundations, theory, and practice Hoboken, NJ: John Wiley & Sons  

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  • Reading the tea leaves from Windows Azure support

    - by jamiet
    A few idle thoughts… Three months ago I had an issue regarding Windows Azure where I was unable to login to the management portal. At the time I contacted Azure support, the issue was soon resolved and I thought no more about it. Until today that is when I received an email from Azure support providing a detailed analysis of the root cause, the fix and moreover precise details about when and where things occurred. The email itself is interesting and I have included the entirety of it below. A few things were interesting to me: The level of detail and the diligence in investigating and reporting the issue I found really rather impressive. They even outline the number of users that were affected (127 in case you can’t be bothered reading). Compare this to the quite pathetic support that another division within Microsoft, Skype, provided to Greg Low recently: Skype support and dead parrot sketches   This line: “Windows Azure performed a planned change from using the Microsoft account service (formerly Windows Live ID) to the Azure Active Directory (AAD) as its primary authentication mechanism on August 24th. This change was made to enable future innovation in the area of authentication – particularly for organizationally owned identities, identity federation, stronger authentication methods and compliance certification. ” I also found to be particularly interesting. I have long thought that one of the reasons Microsoft has proved to be such a money-making machine in the enterprise is because they provide the infrastructure and then upsell on top of that – and nothing is more infrastructural than Active Directory. It has struck me of late that they are trying to make the same play of late in the cloud by tying all their services into Azure Active Directory and here we see a clear indication of that by making AAD the authentication mechanism for anyone using Windows Azure. I get the feeling that we’re going to hear much much more about AAD in the future; isn’t it about time we could log on to SQL Azure Windows Azure SQL Database without resorting to SQL authentication, for example? And why do Microsoft have two identity providers – Microsoft Account (aka Windows Live ID) and AAD – isn’t it about time those things were combined? As I said, just some idle thoughts. Below is the transcript of the email if you are interested. @Jamiet  This is regarding the support request <redacted> where in you were not able to login into the windows azure management portal with live id. We are providing you with the summary, root cause analysis and information about permanent fix: Incident Title: You were unable to access Windows Azure Portal after Microsoft Account to Azure Active Directory account Migration. Service Impacted: Management Portal Incident Start Date and Time: 8/24/2012 4:30:00 PM Date and Time Service was Restored: 10/17/2012 12:00:00 AM Summary: Windows Azure performed a planned change from using the Microsoft account service (formerly Windows Live ID) to the Azure Active Directory (AAD) as its primary authentication mechanism on August 24th.   This change was made to enable future innovation in the area of authentication – particularly for organizationally owned identities, identity federation, stronger authentication methods and compliance certification.   While this migration was largely transparent to Windows Azure users, a small number of users whose sign-in names were part of a Windows Live Custom Domain were unable to login.   This incompatibility was not discovered during the Quality Assurance testing phase prior to the migration. Customer Impact: Customers whose sign-in names were part of a Windows Live Custom Domain were unable to sign-in the Management Portal after ~4:00 p.m. PST on August 24th, 2012.   We determined that the issue did impact at least 127 users in 98 of these Windows Live Custom Domains and had a maximum potential impact of 1,110 users in total. Root Cause: The root cause of the issue was an incompatibility in the AAD authentication service to handle logins from Microsoft accounts whose sign-in names were part of a Windows Live Custom Domains.  This issue was not discovered during the Quality Assurance testing phase prior to the migration from Microsoft Account (MSA) to AAD. Mitigations: The issue was mitigated for the majority of affected users by 8:20 a.m. PST on August 25th, 2012 by running some internal scripts to correct many known Windows Live Custom Domains.   The remaining affected domains fell into two categories: Windows Live Custom Domains that were not corrected by 8/25/2012. An additional 48 Windows Live Custom Domains were fixed in the weeks following the incident within 2 business days after the AAD team received an escalation from product support regarding those accounts. Windows Live Custom domains that were also provisioned in Office365. Some of the affected Windows Live Custom Domains had already been provisioned in AAD because their owners signed up for Office365 which is a service that also uses AAD.   In these cases the Azure customers had to work around the issue by renaming their Microsoft Account or using a different Microsoft Account to administer their Azure subscription. Permanent Fix: The Azure Active Directory team permanently fixed the issue for all customers on 10/17/2012 in an upgraded release of the AAD service.

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  • How to fix Ubuntu 12.04.3 boot to black screen full of errors in white text, after upgrading on dell inspiron 1501

    - by Ibuntu
    I am running a Dell Inspiron 1501 I use Linux only. No Microsoft or Apple operating systems (or really anything closed-source). I've only been using Linux for a little over a year but I'm starting to gain a comfortable level of familiarity with the system and terminology. I've been having some issues with Quantel Quetzal and Raring Ringtail, especially with older hardware, so I opted to install Ubuntu 12.04.3 Precise Pangolin on the Inspiron 1501. I checked my MD5 sum after downloading my ISO and all was good. I have in fact used this iso/dvd to install Precise Pangolin successfully on a few other systems (some of which are even older than this laptop). Install goes fine. The wireless card doesn't work out of the box but this is a known issue which is fairly easy to fix. So, first thing I did was open up a terminal and run sudo apt-get update && sudo apt-get upgrade which, part way through, crashed (I assume lightdm and possibly X) and took me to a black screen filled with white lines of text that were either errors or just the ouputs of commands. The reason I say that is because I was unable to gleam any useful information from the output on the screen. I did take a picture however and will post a link. After that, every time I boot the system it goes right to that black screen posting all the error messages or output in white text. I never get a purple Ubuntu splash, so from what I can tell after reading this wiki article: https://wiki.ubuntu.com/X/Troubleshooting/BlankScreen That means that after the kernel is selected, it is unable to correctly implement the settings it needs. If the purple splash never shows, the frame buffer was never set correctly right? This leads me to believe that it could be a kernel issue? The wiki suggested to try and pinpoint the issue by rolling back kernels until I find one that works. Is this my best option? I think I'm going to give it a try anyways and will let everyone know if I am able to solve the issue this way. I have since done a few reinstalls and some trouble-shooting including a couple hours scouring the net for anyone with any kind of similar issue. Most of the issues I could find involved getting a black screen after login and none of them said anything about any information output on this black screen. My reinstalls have taught me that there is no issue updating, but as soon as I run sudo apt-get upgrade my system goes to the black screen and every time I boot it up it does the same thing. The only way to fix is by reinstall. I never get any ability to log in. After a hard power off to the laptop (because I cannot use ctrl+alt+del to reboot) when it boots again it goes to the grub boot menu and I can select between regular boot, recovery mode and the two memtest options. I never tried the memtest options but the other two both lead to the same black screen. Some people having a black/blank screen issue claim to have fixed it by using 12.10 or 13.04 but I believe they were having a different issue where they got a black/blank screen after logging in. I think I will still give these images a try, but mostly figured I would just wait another day or two for 13.10. Other things I figured I would try from the following three articles: After logging in, there's a black screen and my cursor, nothing else! in Ubuntu 12.10 Black Screen on Login After Upgrading to 12.04 I can't get to the login screen include opening a terminal using ctrl+alt+f1 and trying a variety of reseting unity, x settings, lightdm (or switching to gdm); but I doubt this will work or that I will even be able to access a terminal. I'm pretty sure the whole system is stuck after it loads the last line on the black screen. I will try these things and post more information when I have. Hopefully someone has an idea in the meantime and I will keep checking back trying to find a solution. Thank you. Here are 3 different pictures of the error message. I had to take with my phone: http://ubuntuone.com/album/0TBBkxmVajJIQQtoN9mVdN

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  • Cloud Deployment Models

    - by B R Clouse
    Normal 0 false false false EN-US X-NONE X-NONE As the cloud paradigm grows in depth and breadth, more readers are approaching the topic for the first time, or from a new perspective.  This blog is a basic review of  cloud deployment models, to help orient newcomers and neophytes. Most cloud deployments today are either private or public. It is also possible to connect a private cloud and a public cloud to form a hybrid cloud. A private cloud is for the exclusive use of an organization. Enterprises, universities and government agencies throughout the world are using private clouds. Some have designed, built and now manage their private clouds. Others use a private cloud that was built by and is now managed by a provider, hosted either onsite or at the provider’s datacenter. Because private clouds are for exclusive use, they are usually the option chosen by organizations with concerns about data security and guaranteed performance. Public clouds are open to anyone with an Internet connection. Because they require no capital investment from their users, they are particularly attractive to companies with limited resources in less regulated environments and for temporary workloads such as development and test environments. Public clouds offer a range of products, from end-user software packages to more basic services such as databases or operating environments. Public clouds may also offer cloud services such as a disaster recovery for a private cloud, or the ability to “cloudburst” a temporary workload spike from a private cloud to a public cloud. These are examples of a hybrid cloud. These are most feasible when the private and public clouds are built with similar technologies. Usually people think of a public cloud in terms of a user role, e.g., “Which public cloud should I consider using?” But someone needs to own and manage that public cloud. The company who owns and operates a public cloud is known as a public cloud provider. Oracle Database Cloud Service, Amazon RDS, database.com and Savvis Symphony Database are examples of public cloud database services. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} When evaluating deployment models, be aware that you can use any or all of the available options. Some workloads may be best-suited for a private cloud, some for a public or hybrid cloud. And you might deploy multiple private clouds in your organization. If you are going to combine multiple clouds, then you want to make sure that each cloud is based on a consistent technology portfolio and architecture. This simplifies management and gives you the greatest flexibility in moving resources and workloads among your different clouds. Oracle’s portfolio of cloud products and services enables both deployment models. Oracle can manage either model. Universities, government agencies and companies in all types of business everywhere in the world are using clouds built with the Oracle portfolio. By employing a consistent portfolio, these customers are able to run all of their workloads – from test and development to the most mission-critical -- in a consistent manner: One Enterprise Cloud, powered by Oracle.   /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Windows 8/Surface Lunch Event Summary

    - by Tim Murphy
    Today was a big day for Microsoft with two separate launch event.  The first for Windows 8 and all of it’s hardware partners.  The second was specifically to introduce the Microsoft Windows 8 Surface tablet.  Below are some of the take-aways I got from the webcasts. Windows 8 Launch The three general area that Microsoft focused on were the release of the OS itself, the public unveiling of the Windows Store and the new devices available from its hardware partners. The release of the OS focused on the fact that it will be available at mid-night tonight for both new PCs and for upgrades.  I can’t say that this interested me that much since it was already known to most people.  I think what they did show well was how easy the OS really is to use. The Windows Store is also not a new feature to those of us who have been running the pre-release versions of Windows 8 or have owned Windows Phone 7 for the past 2 years.  What was interesting is that the Windows Store launches with more apps available than any other platforms store at their respective launch.  I think this says a lot about how Microsoft focuses on the ability of developers to create software and make it available.  The of course were sure to emphasize that the Windows Store has better monetary terms for developers than its competitors. The also showed off the fact that XBox Music streaming is available for to all Windows 8 user for free.  Couple this with the Bing suite of apps that give you news, weather, sports and finance right out of the box and I think most people will find the environment a joy to use. I think the hardware demo, while quick and furious, really show where Windows shine: CHOICE!  They made a statement that over 1000 devices have been certified for Windows 8.  They showed tablets, laptops, desktops, all-in-ones and convertibles.  Since these devices have industry standard connectors they give a much wider variety of accessories and devices that you can use with them. Steve Balmer then came on stage and tried to see how many times he could use the “magical”.  He focused on how the Windows 8 OS is designed to integrate with SkyDrive, Skype and Outlook.com.  He also enforced that they think Windows 8 is the best choice for the Enterprise when it comes to protecting data and integrating across devices including Windows Phone 8. With that we were left to wait for the second event of the day. Surface Launch The second event of the day started with kids with magnets.  Ok, they were adults, but who doesn’t like playing with magnets.  Steven Sinofsky detached and reattached the Surface keyboard repeatedly, clearly enjoying himself.  It turns out that there are 4 magnets in the cover, 2 for alignment and 2 as connectors. They then went to giving us the details on the display.  The 10.6” display is optically bonded to the case and is optimized to reduce glare.  I think this came through very well in the demonstrations. The properties of the case were also a great selling point.  The VaporMg allowed them to drop the device on stage, on purpose, and continue working.  Of course they had to bring out the skate boards made from Surface devices. “It just has to feel right” was the reason they gave for many of their design decisions from the weight and size of the device to the way the kickstand and camera work together.  While this gave you the feeling that the whole process was trial and error you could tell that a lot of science went into the specs.  This included making sure that the magnets were strong enough to hold the cover on and still have a 3 year old remove the cover without effort. I am glad that they also decided the a USB port would be part of the spec since it give so many options.  They made the point that this allows Surface to leverage over 420 million existing devices.  That works for me. The last feature that I really thought was important was the microSD port.  Begin stuck with the onboard memory has been an aggravation of mine with many of the devices in the market today. I think they did job of really getting the audience to understand why you want this platform and this particular device.  Using personal examples like creating a video of a birthday party and being in it or the fact that the device was being used to live blog the event and control the lights and presentation.  They showed very well that it was not only fun but very capable of getting real work done.  Handing out tablets to the crowd didn’t hurt either.  In the end I really wanted a Surface even though I really have no need for one on a daily basis.  Great job Microsoft! del.icio.us Tags: Windows 8,Win8,Windows 8 Luanch

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  • Deduping your redundancies

    - by nospam(at)example.com (Joerg Moellenkamp)
    Robin Harris of Storagemojo pointed to an interesting article about about deduplication and it's impact to the resiliency of your data against data corruption on ACM Queue. The problem in short: A considerable number of filesystems store important metadata at multiple locations. For example the ZFS rootblock is copied to three locations. Other filesystems have similar provisions to protect their metadata. However you can easily proof, that the rootblock pointer in the uberblock of ZFS for example is pointing to blocks with absolutely equal content in all three locatition (with zdb -uu and zdb -r). It has to be that way, because they are protected by the same checksum. A number of devices offer block level dedup, either as an option or as part of their inner workings. However when you store three identical blocks on them and the devices does block level dedup internally, the device may just deduplicated your redundant metadata to a block stored just once that is stored on the non-voilatile storage. When this block is corrupted, you have essentially three corrupted copies. Three hit with one bullet. This is indeed an interesting problem: A device doing deduplication doesn't know if a block is important or just a datablock. This is the reason why I like deduplication like it's done in ZFS. It's an integrated part and so important parts don't get deduplicated away. A disk accessed by a block level interface doesn't know anything about the importance of a block. A metadata block is nothing different to it's inner mechanism than a normal data block because there is no way to tell that this is important and that those redundancies aren't allowed to fall prey to some clever deduplication mechanism. Robin talks about this in regard of the Sandforce disk controllers who use a kind of dedup to reduce some of the nasty effects of writing data to flash, but the problem is much broader. However this is relevant whenever you are using a device with block level deduplication. It's just the point that you have to activate it for most implementation by command, whereas certain devices do this by default or by design and you don't know about it. However I'm not perfectly sure about that ? given that storage administration and server administration are often different groups with different business objectives I would ask your storage guys if they have activated dedup without telling somebody elase on their boxes in order to speak less often with the storage sales rep. The problem is even more interesting with ZFS. You may use ditto blocks to protect important data to store multiple copies of data in the pool to increase redundancy, even when your pool just consists out of one disk or just a striped set of disk. However when your device is doing dedup internally it may remove your redundancy before it hits the nonvolatile storage. You've won nothing. Just spend your disk quota on the the LUNs in the SAN and you make your disk admin happy because of the good dedup ratio However you can just fall in this specific "deduped ditto block"trap when your pool just consists out of a single device, because ZFS writes ditto blocks on different disks, when there is more than just one disk. Yet another reason why you should spend some extra-thought when putting your zpool on a single LUN, especially when the LUN is sliced and dices out of a large heap of storage devices by a storage controller. However I have one problem with the articles and their specific mention of ZFS: You can just hit by this problem when you are using the deduplicating device for the pool. However in the specifically mentioned case of SSD this isn't the usecase. Most implementations of SSD in conjunction with ZFS are hybrid storage pools and so rotating rust disk is used as pool and SSD are used as L2ARC/sZIL. And there it simply doesn't matter: When you really have to resort to the sZIL (your system went down, it doesn't matter of one block or several blocks are corrupt, you have to fail back to the last known good transaction group the device. On the other side, when a block in L2ARC is corrupt, you simply read it from the pool and in HSP implementations this is the already mentioned rust. In conjunction with ZFS this is more interesting when using a storage array, that is capable to do dedup and where you use LUNs for your pool. However as mentioned before, on those devices it's a user made decision to do so, and so it's less probable that you deduplicating your redundancies. Other filesystems lacking acapability similar to hybrid storage pools are more "haunted" by this problem of SSD using dedup-like mechanisms internally, because those filesystem really store the data on the the SSD instead of using it just as accelerating devices. However at the end Robin is correct: It's jet another point why protecting your data by creating redundancies by dispersing it several disks (by mirror or parity RAIDs) is really important. No dedup mechanism inside a device can dedup away your redundancy when you write it to a totally different and indepenent device.

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  • Stumbling Through: Visual Studio 2010 (Part II)

    I would now like to expand a little on what I stumbled through in part I of my Visual Studio 2010 post and touch on a few other features of VS 2010.  Specifically, I want to generate some code based off of an Entity Framework model and tie it up to an actual data source.  Im not going to take the easy way and tie to a SQL Server data source, though, I will tie it to an XML data file instead.  Why?  Well, why not?  This is purely for learning, there are probably much better ways to get strongly-typed classes around XML but it will force us to go down a path less travelled and maybe learn a few things along the way.  Once we get this XML data and the means to interact with it, I will revisit data binding to this data in a WPF form and see if I cant get reading, adding, deleting, and updating working smoothly with minimal code.  To begin, I will use what was learned in the first part of this blog topic and draw out a data model for the MFL (My Football League) - I dont want the NFL to come down and sue me for using their name in this totally football-related article.  The data model looks as follows, with Teams having Players, and Players having a position and statistics for each season they played: Note that when making the associations between these entities, I was given the option to create the foreign key but I only chose to select this option for the association between Player and Position.  The reason for this is that I am picturing the XML that will contain this data to look somewhat like this: <MFL> <Position/> <Position/> <Position/> <Team>     <Player>         <Statistic/>     </Player> </Team> </MFL> Statistic will be under its associated Player node, and Player will be under its associated Team node no need to have an Id to reference it if we know it will always fall under its parent.  Position, however, is more of a lookup value that will not have any hierarchical relationship to the player.  In fact, the Position data itself may be in a completely different xml file (something Id like to play around with), so in any case, a player will need to reference the position by its Id. So now that we have a simple data model laid out, I would like to generate two things based on it:  A class for each entity with properties corresponding to each entity property An IO class with methods to get data for each entity, either all instances, by Id or by parent. Now my experience with code generation in the past has consisted of writing up little apps that use the code dom directly to regenerate code on demand (or using tools like CodeSmith).  Surely, there has got to be a more fun way to do this given that we are using the Entity Framework which already has built-in code generation for SQL Server support.  Lets start with that built-in stuff to give us a base to work off of.  Right click anywhere in the canvas of our model and select Add Code Generation Item: So just adding that code item seemed to do quite a bit towards what I was intending: It apparently generated a class for each entity, but also a whole ton more.  I mean a TON more.  Way too much complicated code was generated now that code is likely to be a black box anyway so it shouldnt matter, but we need to understand how to make this work the way we want it to work, so lets get ready to do some stumbling through that text template (tt) file. When I open the .tt file that was generated, right off the bat I realize there is going to be trouble there is no color coding, no intellisense no nothing!  That is going to make stumbling through more like groping blindly in the dark while handcuffed and hopping on one foot, which was one of the alternate titles I was considering for this blog.  Thankfully, the community comes to my rescue and I wont have to cast my mind back to the glory days of coding in VI (look it up, kids).  Using the Extension Manager (Available under the Tools menu), I did a quick search for tt editor in the Online Gallery and quickly found the Tangible T4 Editor: Downloading and installing this was a breeze, and after doing so I got some color coding and intellisense while editing the tt files.  If you will be doing any customizing of tt files, I highly recommend installing this extension.  Next, well see if that is enough help for us to tweak that tt file to do the kind of code generation that we wantDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Using XA Transactions in Coherence-based Applications

    - by jpurdy
    While the costs of XA transactions are well known (e.g. increased data contention, higher latency, significant disk I/O for logging, availability challenges, etc.), in many cases they are the most attractive option for coordinating logical transactions across multiple resources. There are a few common approaches when integrating Coherence into applications via the use of an application server's transaction manager: Use of Coherence as a read-only cache, applying transactions to the underlying database (or any system of record) instead of the cache. Use of TransactionMap interface via the included resource adapter. Use of the new ACID transaction framework, introduced in Coherence 3.6.   Each of these may have significant drawbacks for certain workloads. Using Coherence as a read-only cache is the simplest option. In this approach, the application is responsible for managing both the database and the cache (either within the business logic or via application server hooks). This approach also tends to provide limited benefit for many workloads, particularly those workloads that either have queries (given the complexity of maintaining a fully cached data set in Coherence) or are not read-heavy (where the cost of managing the cache may outweigh the benefits of reading from it). All updates are made synchronously to the database, leaving it as both a source of latency as well as a potential bottleneck. This approach also prevents addressing "hot data" problems (when certain objects are updated by many concurrent transactions) since most database servers offer no facilities for explicitly controlling concurrent updates. Finally, this option tends to be a better fit for key-based access (rather than filter-based access such as queries) since this makes it easier to aggressively invalidate cache entries without worrying about when they will be reloaded. The advantage of this approach is that it allows strong data consistency as long as optimistic concurrency control is used to ensure that database updates are applied correctly regardless of whether the cache contains stale (or even dirty) data. Another benefit of this approach is that it avoids the limitations of Coherence's write-through caching implementation. TransactionMap is generally used when Coherence acts as system of record. TransactionMap is not generally compatible with write-through caching, so it will usually be either used to manage a standalone cache or when the cache is backed by a database via write-behind caching. TransactionMap has some restrictions that may limit its utility, the most significant being: The lock-based concurrency model is relatively inefficient and may introduce significant latency and contention. As an example, in a typical configuration, a transaction that updates 20 cache entries will require roughly 40ms just for lock management (assuming all locks are granted immediately, and excluding validation and writing which will require a similar amount of time). This may be partially mitigated by denormalizing (e.g. combining a parent object and its set of child objects into a single cache entry), at the cost of increasing false contention (e.g. transactions will conflict even when updating different child objects). If the client (application server JVM) fails during the commit phase, locks will be released immediately, and the transaction may be partially committed. In practice, this is usually not as bad as it may sound since the commit phase is usually very short (all locks having been previously acquired). Note that this vulnerability does not exist when a single NamedCache is used and all updates are confined to a single partition (generally implying the use of partition affinity). The unconventional TransactionMap API is cumbersome but manageable. Only a few methods are transactional, primarily get(), put() and remove(). The ACID transactions framework (accessed via the Connection class) provides atomicity guarantees by implementing the NamedCache interface, maintaining its own cache data and transaction logs inside a set of private partitioned caches. This feature may be used as either a local transactional resource or as logging XA resource. However, a lack of database integration precludes the use of this functionality for most applications. A side effect of this is that this feature has not seen significant adoption, meaning that any use of this is subject to the usual headaches associated with being an early adopter (greater chance of bugs and greater risk of hitting an unoptimized code path). As a result, for the moment, we generally recommend against using this feature. In summary, it is possible to use Coherence in XA-oriented applications, and several customers are doing this successfully, but it is not a core usage model for the product, so care should be taken before committing to this path. For most applications, the most robust solution is normally to use Coherence as a read-only cache of the underlying data resources, even if this prevents taking advantage of certain product features.

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  • IsNumeric() Broken? Only up to a point.

    - by Phil Factor
    In SQL Server, probably the best-known 'broken' function is poor ISNUMERIC() . The documentation says 'ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0. ISNUMERIC returns 1 for some characters that are not numbers, such as plus (+), minus (-), and valid currency symbols such as the dollar sign ($).'Although it will take numeric data types (No, I don't understand why either), its main use is supposed to be to test strings to make sure that you can convert them to whatever numeric datatype you are using (int, numeric, bigint, money, smallint, smallmoney, tinyint, float, decimal, or real). It wouldn't actually be of much use anyway, since each datatype has different rules. You actually need a RegEx to do a reasonably safe check. The other snag is that the IsNumeric() function  is a bit broken. SELECT ISNUMERIC(',')This cheerfully returns 1, since it believes that a comma is a currency symbol (not a thousands-separator) and you meant to say 0, in this strange currency.  However, SELECT ISNUMERIC(N'£')isn't recognized as currency.  '+' and  '-' is seen to be numeric, which is stretching it a bit. You'll see that what it allows isn't really broken except that it doesn't recognize Unicode currency symbols: It just tells you that one numeric type is likely to accept the string if you do an explicit conversion to it using the string. Both these work fine, so poor IsNumeric has to follow suit. SELECT  CAST('0E0' AS FLOAT)SELECT  CAST (',' AS MONEY) but it is harder to predict which data type will accept a '+' sign. SELECT  CAST ('+' AS money) --0.00SELECT  CAST ('+' AS INT)   --0SELECT  CAST ('+' AS numeric)/* Msg 8115, Level 16, State 6, Line 4 Arithmetic overflow error converting varchar to data type numeric.*/SELECT  CAST ('+' AS FLOAT)/*Msg 8114, Level 16, State 5, Line 5Error converting data type varchar to float.*/> So we can begin to say that the maybe IsNumeric isn't really broken, but is answering a silly question 'Is there some numeric datatype to which i can convert this string? Almost, but not quite. The bug is that it doesn't understand Unicode currency characters such as the euro or franc which are actually valid when used in the CAST function. (perhaps they're delaying fixing the euro bug just in case it isn't necessary).SELECT ISNUMERIC (N'?23.67') --0SELECT  CAST (N'?23.67' AS money) --23.67SELECT ISNUMERIC (N'£100.20') --1SELECT  CAST (N'£100.20' AS money) --100.20 Also the CAST function itself is quirky in that it cannot convert perfectly reasonable string-representations of integers into integersSELECT ISNUMERIC('200,000')       --1SELECT  CAST ('200,000' AS INT)   --0/*Msg 245, Level 16, State 1, Line 2Conversion failed when converting the varchar value '200,000' to data type int.*/  A more sensible question is 'Is this an integer or decimal number'. This cuts out a lot of the apparent quirkiness. We do this by the '+E0' trick. If we want to include floats in the check, we'll need to make it a bit more complicated. Here is a small test-rig. SELECT  PossibleNumber,         ISNUMERIC(CAST(PossibleNumber AS NVARCHAR(20)) + 'E+00') AS Hack,        ISNUMERIC (PossibleNumber + CASE WHEN PossibleNumber LIKE '%E%'                                          THEN '' ELSE 'E+00' END) AS Hackier,        ISNUMERIC(PossibleNumber) AS RawIsNumericFROM    (SELECT CAST(',' AS NVARCHAR(10)) AS PossibleNumber          UNION SELECT '£' UNION SELECT '.'         UNION SELECT '56' UNION SELECT '456.67890'         UNION SELECT '0E0' UNION SELECT '-'         UNION SELECT '-' UNION SELECT '.'         UNION  SELECT N'?' UNION SELECT N'¢'        UNION  SELECT N'?' UNION SELECT N'?34.56'         UNION SELECT '-345' UNION SELECT '3.332228E+09') AS examples Which gives the result ... PossibleNumber Hack Hackier RawIsNumeric-------------- ----------- ----------- ------------? 0 0 0- 0 0 1, 0 0 1. 0 0 1¢ 0 0 1£ 0 0 1? 0 0 0?34.56 0 0 00E0 0 1 13.332228E+09 0 1 1-345 1 1 1456.67890 1 1 156 1 1 1 I suspect that this is as far as you'll get before you abandon IsNumeric in favour of a regex. You can only get part of the way with the LIKE wildcards, because you cannot specify quantifiers. You'll need full-blown Regex strings like these ..[-+]?\b[0-9]+(\.[0-9]+)?\b #INT or REAL[-+]?\b[0-9]{1,3}\b #TINYINT[-+]?\b[0-9]{1,5}\b #SMALLINT.. but you'll get even these to fail to catch numbers out of range.So is IsNumeric() an out and out rogue function? Not really, I'd say, but then it would need a damned good lawyer.

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  • Control HelpButton, HelpRequested, HelpButtonClicked - Instant help for windows Dialog Form components

    Instant help for windows dialog components is a great feature and very much known since windows 98. but I saw many many people are not aware it and query on Google to get help, but “help button” for dialogs helps you or your customers to get the help instantly. Every dialog window has help icon if that dialog was coded to enable it. it really helps to know the functionality of the components quickly. For example I was trying to pint a document from acrobat reader and opened printer properties to print the content front and back of the paper. If you observe there is a help button before close button. To get help on options of “Print on Both Sides” you would need to click on help button first and then click on the area on which you want to see the help. above picture shows help text for the options of “Print on Both Sides”. If you would like to get the help using keyboard you can use F1 key. Help button can be displayed only if minimize button and maximize button both are not shown unless you want go with custom buttons. below is the way if you want to get Help button for windows forms.   In this sample demo I want to have a checkbox and need to show help when I click on F1 on check box. So I created a form which country check box and help label as show in adjacent picture. Below is the code for your code bind file. using System; using System.Windows.Forms; namespace WindowsFormsApplication1 {     public partial classForm1: Form    {         publicForm1()         {             InitializeComponent();         }         private void Form1_Load(objectsender, EventArgs e)         {             this.Text = "Help Button Demo Form";             lblHelp.Text = "Press F1 on any component to get Instant Help";             this.HelpButton = true;             this.MaximizeBox = false;             this.MinimizeBox = false;             chkCountry.Tag = "Check or Uncheck Coutry Check Box";             chkCountry.HelpRequested += newHelpEventHandler(chkCountry_HelpRequested);             chkCountry.MouseLeave += newEventHandler(chkCountry_MouseLeave);         }         void chkCountry_HelpRequested(objectsender, HelpEventArgs hlpevent)         {             ControlrequestingControl = (Control)sender;             lblHelp.Text = (string)requestingControl.Tag;             hlpevent.Handled = true;         }         void chkCountry_MouseLeave(objectsender, EventArgs e)         {             lblHelp.Text = "Press F1 on any component to get Instant Help";         }     } } In above code  “HelpRequested” is an event will be fired when you click on F1 on Country checkbox. I stored the help information in the checkbox property called “Tag”. You might also maintain a property file to keep help text for each component differently. If you click on F1 when focus is on main form instead on individual component then generally separate help window opens. This can be done using the event “Form.HelpRequested” to open help windows as in below code. this.HelpRequested += newHelpEventHandler(Form1_HelpRequested); voidForm1_HelpRequested(objectsender, HelpEventArgs hlpevent) {     frmHelp.Show(); } span.fullpost {display:none;}

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  • The architecture and technologies to use for a secure, fast, reliable and easily scalable web application

    - by DSoul
    ^ For actual questions, skip to the lists down below I understand, that his is a vague topic, but please, before you turn the other way and disregard me, hear me out. I am currently doing research for a web application(I don't know if application is the correct word for it, but I will proceed w/ that for now), that one day might need to be everything mentioned in the title. I am bound by nothing. That means that every language, OS and framework is acceptable, but only if it proves it's usefulness. And if you are going to say, that scalability and speed depend on the code I write for this application, then I agree, but I am just trying to find something, that wouldn't stand in my way later on. I have done quite a bit reading on this subject, but I still don't have a clear picture, to what suits my needs, so I come to you, StackOverflow, to give me directions. I know you all must be wondering what I'm building, but I assure you, that it doesn't matter. I have heard of 12 factor app though, if you have any similar guidelines or what is, to suggest the please, go ahead. For the sake of keeping your answers as open as possible, I'm not gonna provide you my experience regarding anything written in this question. ^ Skippers, start here First off - the weights of the requirements are probably something like that (on a scale of 10): Security - 10 Speed - 5 Reliability (concurrency) - 7.5 Scalability - 10 Speed and concurrency are not a top priority, in the sense, that the program can be CPU intensive, and therefore slow, and only accept a not-that-high number of concurrent users, but both of these factors must be improvable by scaling the system Anyway, here are my questions: How many layers should the application have, so it would be future-proof and could best fulfill the aforementioned requirements? For now, what I have in mind is the most common version: Completely separated front end, that might be a web page or an MMI application or even both. Some middle-ware handling communication between the front and the back end. This is probably a server that communicates w/ the front end via HTTP. How the communication w/ the back end should be handled is probably dependent on the back end. The back end. Something that handles data through resources like DB and etc. and does various computations w/ the data. This, as the highest priority part of the software, must be easily spread to multiple computers later on and have no known security holes. I think ideally the middle-ware should send a request to a queue from where one of the back end processes takes this request, chops it up to smaller parts and buts these parts of the request back onto the same queue as the initial request, after what these parts will be then handled by other back end processes. Something *map-reduce*y, so to say. What frameworks, languages and etc. should these layers use? The technologies used here are not that important at this moment, you can ignore this part for now I've been pointed to node.js for this part. Do you guys know any better alternatives, or have any reasons why I should (not) use node.js for this particular job. I actually have no good idea, what to use for this job, there are too many options out there, so please direct me. This part (and the 2. one also, I think) depend a lot on the OS, so suggest any OSs alongside w/ the technologies/frameworks. Initially, all computers (or 1 for starters) hosting the back end are going to be virtual machines. Please do give suggestions to any part of the question, that you feel you have comprehensive knowledge and/or experience of. And also, point out if you feel that any part of the current set-up means an instant (or even distant) failure or if I missed a very important aspect to consider. I'm not looking for a definitive answer for how to achieve my goals, because there certainly isn't one, for I haven't provided you w/ all the required information. I'm just looking for recommendations and directions on what to look into. Also, bare in mind, that this isn't something that I have to get done quickly, to sell and let it be re-written by the new owner (which, I've been told for multiple times, is what I should aim for). I have all the time in the world and I really just want to learn doing something really high-end. Also, excuse me if my language isn't the best, I'm not a native. Anyway. Thanks in advance to anyone, who takes the time to help me out here. PS. When I do seem to come up w/ a good architecture/design for this project, I will certainly make it an open project and keep you guys up to date w/ it's development. As in what you could have told me earlier and etc. For obvious reasons the very same question got closed on SO, but could you guys still help me?.

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  • Rails3 server and bundler error: uninitialized constant Bundler (NameError)

    - by .yandex.rurap-kasta
    I just install rails 3 and all gems that it need, but when I try to start server, it says about problem in boot script. [rap-kasta@acerAspire testR3]$ script/rails server /home/rap-kasta/tmp/testR3/config/boot.rb:7:in `rescue in <top (required)>': uninitialized constant Bundler (NameError) from /home/rap-kasta/tmp/testR3/config/boot.rb:2:in `<top (required)>' from script/rails:9:in `require' from script/rails:9:in `<main> So, I tried to reinstall Bundler, install "pre"-version (but really it has version number lower then i install by gem install bundler Now there are next gems in system: abstract (1.0.0) actionmailer (3.0.0.beta, 2.3.5, 2.3.4) actionpack (3.0.0.beta, 2.3.5, 2.3.4) activemodel (3.0.0.beta) activerecord (3.0.0.beta, 2.3.5, 2.3.4) activeresource (3.0.0.beta, 2.3.5, 2.3.4) activesupport (3.0.0.beta, 2.3.5, 2.3.4) arel (0.2.1, 0.2.pre) builder (2.1.2) bundler (0.9.5) erubis (2.6.5) fxri (0.3.7) fxruby (1.6.20) i18n (0.3.3) jemini (2010.1.24, 2010.1.5) mail (2.1.2) memcache-client (1.7.8) mime-types (1.16) mysql (2.8.1) nifty-generators (0.3.2, 0.3.0) rack (1.1.0, 1.0.1, 1.0.0) rack-mount (0.5.1, 0.4.0) rack-openid (0.2.3, 0.2.2) rack-test (0.5.3) rails (3.0.0.beta, 2.3.5, 2.3.4) railties (3.0.0.beta) rake (0.8.7) rawr (1.3.8) RedCloth (4.2.2) ruby-mysql (3.0.2) ruby-openid (2.1.7) rubygems-update (1.3.5) rubyzip (0.9.4, 0.9.1) rubyzip2 (2.0.1) sqlite3-ruby (1.2.5) text-format (1.0.0) text-hyphen (1.0.0) thor (0.13.2, 0.13.1) tzinfo (0.3.16) Also, there is same error with rails console and similar with bundle check: [rap-kasta@acerAspire testR3]$ bundle check /usr/lib/ruby/gems/1.9.1/gems/bundler-0.9.5/bin/bundle:12:in `rescue in <top (required)>': uninitialized constant Bundler::BundlerError (NameError) from /usr/lib/ruby/gems/1.9.1/gems/bundler-0.9.5/bin/bundle:10:in `<top (required)>' from /usr/bin/bundle:19:in `load' from /usr/bin/bundle:19:in `<main>'

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  • System.Runtime.InteropServices.COMException (0x80070008): Not enough storage is available to process

    - by Darryl Braaten
    I am trying to diagnose this exception. "System.Runtime.InteropServices.COMException (0x80070008): Not enough storage is available to process this command. (Exception from HRESULT: 0x80070008) at System.Runtime.Remoting.RemotingServices.AllocateUninitializedObject(RuntimeType objectType) at System.Runtime.Remoting.RemotingServices.AllocateUninitializedObject(Type objectType) at System.Runtime.Remoting.Activation.ActivationServices.CreateInstance(Type serverType) at System.Runtime.Remoting.Activation.ActivationServices.IsCurrentContextOK(Type serverType, Object[] props, Boolean bNewObj) at Oracle.DataAccess.Client.CThreadPool..ctor() at Oracle.DataAccess.Client.OracleCommand.set_CommandTimeout(Int32 value) ... It does not look like any of the normal types of "storage" have hit any limits. The application is using about 400MB of memory, 70 threads, 2000 handles and the hard drive has many GB free. The machine is running Windows 2003 Enterprise server with 16GB of RAM so memory shouldn't be an issue. The application is running as a windows service so there are no GDI objects being used. Running out of GDI handles is a common cause of this exception. Database connections, commands & readers are all all wrapped with using blocks so they should be getting cleaned up correctly.

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  • WCF ChannelFactory caching

    - by Myles J
    I've just read this great article on WCF ChannelFactory caching by Wenlong Dong. My question is simply how can you actually prove that the ChannelFactory is in fact being cached between calls? I've followed the rules regarding the ClientBase’s constructors. We are using the following overloaded constructor on our object that inherits from ClientBase: ClientBase(string endpointConfigurationName, EndpointAddress remoteAddress); In the article mentioned above it is stated that: For these constructors, all arguments (including default ones) are in the following list: · InstanceContext callbackInstance · string endpointConfigurationName · EndpointAddress remoteAddress As long as these three arguments are the same when ClientBase is constructed, we can safely assume that the same ChannelFactory can be used. Fortunately, String and EndpointAddress types are immutable, i.e., we can make simple comparison to determine whether two arguments are the same. For InstanceContext, we can use Object reference comparison. The type EndpointTrait is thus used as the key of the MRU cache. To test the ChannelFactory cache theory we are checking the Hashcode in the ClientBase constructor e.g. var testHash = RuntimeHelpers.GetHashCode(base.ChannelFactory); The hash value is different between calls which makes us think that the ChannelFactory isn't actually cached. Any thoughts? Regards Myles

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  • Make a Perl-style regex interpreter behave like a basic or extended regex interpreter

    - by Barry Brown
    I am writing a tool to help students learn regular expressions. I will probably be writing it in Java. The idea is this: the student types in a regular expression and the tool shows which parts of a text will get matched by the regex. Simple enough. But I want to support several different regex "flavors" such as: Basic regular expressions (think: grep) Extended regular expressions (think: egrep) A subset of Perl regular expressions, including the character classes \w, \s, etc. Sed-style regular expressions Java has the java.util.Regex class, but it supports only Perl-style regular expressions, which is a superset of the basic and extended REs. What I think I need is a way to take any given regular expression and escape the meta-characters that aren't part of a given flavor. Then I could give it to the Regex object and it would behave as if it was written for the selected RE interpreter. For example, given the following regex: ^\w+[0-9]{5}-(\d{4})?$ As a basic regular expression, it would be interpreted as: ^\\w\+[0-9]\{5\}-\(\\d\{4\}\)\?$ As an extended regular expression, it would be: ^\\w+[0-9]{5}-(\\d{4})?$ And as a Perl-style regex, it would be the same as the original expression. Is there a "regular expression for regular expressions" than I could run through a regex search-and-replace to quote the non-meta characters? What else could I do? Are there alternative Java classes I could use?

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