Search Results

Search found 18 results on 1 pages for 'brash equilibrium'.

Page 1/1 | 1 

  • Netlogo Programming question - Chemical Equilibrium temperature and pressure implementation

    - by user286190
    Hi I am trying to code something in Netlogo..I am using an existing model Chemical Equilibrium and am trying to implement the following: turtles-own [speed ] ask turtles [ ;; set velocity ( ambient-temperature = 30 ) ;; fd velocity if temp > 40 [ "speed" increases of turtles ] ifelse temperature < 30 [ speed of turtles decreases] ] ;; to temp but it does not seem to work (it temperature is more than 40 the speed of the turtles increases if the temperature is less than 30 the speed of the turtles decreases) temperature is a slider on the model the same for pressure ask turtles [ ;; if pressure > 50 then speed increases of turtles ;; if pressure < 50 then speed decreases of turtles ] ;; to pressure thanks

    Read the article

  • what is the best algorithm to use for this problem

    - by slim
    Equilibrium index of a sequence is an index such that the sum of elements at lower indexes is equal to the sum of elements at higher indexes. For example, in a sequence A: A[0]=-7 A[1]=1 A[2]=5 A[3]=2 A[4]=-4 A[5]=3 A[6]=0 3 is an equilibrium index, because: A[0]+A[1]+A[2]=A[4]+A[5]+A[6] 6 is also an equilibrium index, because: A[0]+A[1]+A[2]+A[3]+A[4]+A[5]=0 (sum of zero elements is zero) 7 is not an equilibrium index, because it is not a valid index of sequence A. If you still have doubts, this is a precise definition: the integer k is an equilibrium index of a sequence if and only if and . Assume the sum of zero elements is equal zero. Write a function int equi(int[] A); that given a sequence, returns its equilibrium index (any) or -1 if no equilibrium indexes exist. Assume that the sequence may be very long.

    Read the article

  • MS Access ADP front end and SQL Server back end for field data collection?

    - by Brash Equilibrium
    I am an anthropologist. I am going to the field and will use a netbook to collect survey data. The survey forms will need to allow me to enter data into multiple tables, search tables, allow subforms, and be fast enough to not slow down my interview. I have considered storing the data in a SQL Server Express 2008 R2 server (there will be a lot of data) while using a Microsoft Access data project as a front end. To cut down the number of steps required to collect and store data, I'm considering using the netbook for both data storage and collection (after reading this article about SQL Server on a netbook). My questions are: (1) Is there a simpler solution that is also gratis (gratis because I already have a MS Access license from my workplace, and SQL Server Express is, obviously, free)? (2) Does my idea to store and collect data using the netbook make sense? Thank you.

    Read the article

  • What is the difference between LR, SLR, and LALR parsers?

    - by equilibrium
    What is the actual difference between LR, SLR, and LALR parsers? I know that SLR and LALR are types of LR parsers, but what is the actual difference as far as their parsing tables are concerned? And how to show whether a grammar is LR, SLR, or LALR? For an LL grammar we just have to show that any cell of the parsing table should not contain multiple production rules. Any similar rules for LALR, SLR, and LR? For example, how can we show that the grammar S --> Aa | bAc | dc | bda A --> d is LALR(1) but not SLR(1)?

    Read the article

  • Regular Expression

    - by equilibrium
    Ohh! this regular expression thing is eating my brain up. I have been reading it from Introduction to Automata Theory, Languages and Computer by Hopcroft, Motwani and Ullman. I have solved a few exercises too but could not solve the following even after trying for almost one hr. The problem is to write a regular expression that defines a language consisting of all strings of 0s and 1s except the substring 011. Is the answer (0+1)* - 011 correct ? If not what should be the correct answer for this?

    Read the article

  • regular expression for bit strings with even number of 1s

    - by equilibrium
    Let L= { w in (0+1)* | w has even number of 1s}, i.e. L is the set of all bit strings with even number of 1s. Which one of the regular expressions below represents L? A) (0*10*1)* B) 0*(10*10*)* C) 0*(10*1)* 0* D) 0*1(10*1)* 10* According to me option D is never correct because it does not represent the bit string with zero 1s. But what about the other options? We are concerned about the number of 1s(even or not) not the number of zeros doesn't matter. Then which is the correct option and why?

    Read the article

  • How the number of indexes built on a table can impact performances?

    - by Davide Mauri
    We all know that putting too many indexes (I’m talking of non-clustered index only, of course) on table may produce performance problems due to the overhead that each index bring to all insert/update/delete operations on that table. But how much? I mean, we all agree – I think – that, generally speaking, having many indexes on a table is “bad”. But how bad it can be? How much the performance will degrade? And on a concurrent system how much this situation can also hurts SELECT performances? If SQL Server take more time to update a row on a table due to the amount of indexes it also has to update, this also means that locks will be held for more time, slowing down the perceived performance of all queries involved. I was quite curious to measure this, also because when teaching it’s by far more impressive and effective to show to attended a chart with the measured impact, so that they can really “feel” what it means! To do the tests, I’ve create a script that creates a table (that has a clustered index on the primary key which is an identity column) , loads 1000 rows into the table (inserting 1000 row using only one insert, instead of issuing 1000 insert of one row, in order to minimize the overhead needed to handle the transaction, that would have otherwise ), and measures the time taken to do it. The process is then repeated 16 times, each time adding a new index on the table, using columns from table in a round-robin fashion. Test are done against different row sizes, so that it’s possible to check if performance changes depending on row size. The result are interesting, although expected. This is the chart showing how much time it takes to insert 1000 on a table that has from 0 to 16 non-clustered indexes. Each test has been run 20 times in order to have an average value. The value has been cleaned from outliers value due to unpredictable performance fluctuations due to machine activity. The test shows that in a  table with a row size of 80 bytes, 1000 rows can be inserted in 9,05 msec if no indexes are present on the table, and the value grows up to 88 (!!!) msec when you have 16 indexes on it This means a impact on performance of 975%. That’s *huge*! Now, what happens if we have a bigger row size? Say that we have a table with a row size of 1520 byte. Here’s the data, from 0 to 16 indexes on that table: In this case we need near 22 msec to insert 1000 in a table with no indexes, but we need more that 500msec if the table has 16 active indexes! Now we’re talking of a 2410% impact on performance! Now we can have a tangible idea of what’s the impact of having (too?) many indexes on a table and also how the size of a row also impact performances. That’s why the golden rule of OLTP databases “few indexes, but good” is so true! (And in fact last week I saw a database with tables with 1700bytes row size and 23 (!!!) indexes on them!) This also means that a too heavy denormalization is really not a good idea (we’re always talking about OLTP systems, keep it in mind), since the performance get worse with the increase of the row size. So, be careful out there, and keep in mind the “equilibrium” is the key world of a database professional: equilibrium between read and write performance, between normalization and denormalization, between to few and too may indexes. PS Tests are done on a VMWare Workstation 7 VM with 2 CPU and 4 GB of Memory. Host machine is a Dell Precsioni M6500 with i7 Extreme X920 Quad-Core HT 2.0Ghz and 16Gb of RAM. Database is stored on a SSD Intel X-25E Drive, Simple Recovery Model, running on SQL Server 2008 R2. If you also want to to tests on your own, you can download the test script here: Open TestIndexPerformance.sql

    Read the article

  • Netlogo programming question - is it possible to put balanced chemical equations in a model?

    - by user286190
    hi I was wondering if it was possible to put balanced chemical equations, and if possible including state symbols, in the existing netlogo model that i am using, i havenot seen any examples in the models library so was not sure if it was possible. I wanted the model to be able to allow the user to input a balanced chemical equilibrium equation, or the model displays the the equation so then the user can select from them if they do not want to enter their own any help will be greatly appreciated thanks for example ethane + oxygen -- carbon dioxide + steam C2H6 + O2 -- CO2 + H2O

    Read the article

  • Do game-theoretic considerations stand in the way of this market-based game-mechanic achieving its goals?

    - by BerndBrot
    Mechanic The mechanic is called "market manipulation" and is supposed to work like this: Players can enter the London Stock Exchange (LSE) LSE displays the stock prices of 8 to 10 companies and derivatives. This number is relatively small to ensure that players will collide in their efforts to manipulate the market in their favor. The prices are calculated based on real world prices of these companies and derivatives (in real time) any market manipulations that were conducted by the players any market corrections of the system Players can buy and sell shares with cash, a resource in the game, at current in-game market value Players can manipulate the market, i.e. let the price of a share either rise or fall, by some amount, over a certain period of time. Manipulating the market requires spending certain in-game resources and is therefore limited. The system continuously corrects market manipulations by letting the in-game prices converge towards their real world counterparts at a rate of 2% of the difference between the two per hour. Because of this market correction mechanism, pushing up prices (and screwing down prices) becomes increasingly difficult the higher (lower) the price already is. Goals Players are supposed to collide (and have incentives to collide) in their efforts to manipulate the market in their favor, especially when it comes to manipulation efforts by different groups. Prices should not resolve around any equilibrium points. The more variance the better. Band-wagoning should always involve risk (recognizing that prices start rising should not be a sure sign that they will keep rising so that everybody can make easy profits even when they don't manipulate the market themselves) Question Are there any game-theoretic considerations that prevent the mechanic from achieving these goals?

    Read the article

  • Windows 8 Will be Here Tomorrow; but Should Silverlight be Gone Today?

    - by andrewbrust
    The software industry lives within an interesting paradox. IT in the enterprise moves slowly and cautiously, upgrading only when safe and necessary.  IT interests intentionally live in the past.  On the other hand, developers, and Independent Software Vendors (ISVs) not only want to use the latest and greatest technologies, but this constituency prides itself on gauging tech’s future, and basing its present-day strategy upon it.  Normally, we as an industry manage this paradox with a shrug of the shoulder and musings along the lines of “it takes all kinds.”  Different subcultures have different tendencies.  So be it. Microsoft, with its Windows operating system (OS), can’t take such a laissez-faire view of the world though.  Redmond relies on IT to deploy Windows and (at the very least) influence its procurement, but it also relies on developers to build software for Windows, especially software that has a dependency on features in new versions of the OS.  It must indulge and nourish developers’ fetish for an early birthing of the next generation of software, even as it acknowledges the IT reality that the next wave will arrive on-schedule in Redmond and will travel very slowly to end users. With the move to Windows 8, and the corresponding shift in application development models, this paradox is certainly in place. On the one hand, the next version of Windows is widely expected sometime in 2012, and its full-scale deployment will likely push into 2014 or even later.  Meanwhile, there’s a technology that runs on today’s Windows 7, will continue to run in the desktop mode of Windows 8 (the next version’s codename), and provides absolutely the best architectural bridge to the Windows 8 Metro-style application development stack.  That technology is Silverlight.  And given what we now know about Windows 8, one might think, as I do, that Microsoft ecosystem developers should be flocking to it. But because developers are trying to get a jump on the future, and since many of them believe the impending v5.0 release of Silverlight will be the technology’s last, not everyone is flocking to it; in fact some are fleeing from it.  Is this sensible?  Is it not unprecedented?  What options does it lead to?  What’s the right way to think about the situation? Is v5.0 really the last major version of the technology called Silverlight?  We don’t know.  But Scott Guthrie, the “father” and champion of the technology, left the Developer Division of Microsoft months ago to work on the Windows Azure team, and he took his people with him.  John Papa, who was a very influential Redmond-based evangelist for Silverlight (and is a Visual Studio Magazine author), left Microsoft completely.  About a year ago, when initial suspicion of Silverlight’s demise reached significant magnitude, Papa interviewed Guthrie on video and their discussion served to dispel developers’ fears; but now they’ve moved on. So read into that what you will and let’s suppose, for the sake of argument, speculation that Silverlight’s days of major revision and iteration are over now is correct.  Let’s assume the shine and glimmer has dimmed.  Let’s assume that any Silverlight application written today, and that therefore any investment of financial and human resources made in Silverlight development today, is destined for rework and extra investment in a few years, if the application’s platform needs to stay current. Is this really so different from any technology investment we make?  Every framework, language, runtime and operating system is subject to change, to improvement, to flux and, yes, to obsolescence.  What differs from project to project, is how near-term that obsolescence is and how disruptive the change will be.  The shift from .NET 1.1. to 2.0 was incremental.  Some of the further changes were too.  But the switch from Windows Forms to WPF was major, and the change from ASP.NET Web Services (asmx) to Windows Communication Foundation (WCF) was downright fundamental. Meanwhile, the transition to the .NET development model for Windows 8 Metro-style applications is actually quite gentle.  The finer points of this subject are covered nicely in Magenic’s excellent white paper “Assessing the Windows 8 Development Platform.” As the authors of that paper (including Rocky Lhotka)  point out, Silverlight code won’t just “port” to Windows 8.  And, no, Silverlight user interfaces won’t either; Metro always supports XAML, but that relationship is not commutative.  But the concepts, the syntax, the architecture and developers’ skills map from Silverlight to Windows 8 Metro and the Windows Runtime (WinRT) very nicely.  That’s not a coincidence.  It’s not an accident.  This is a protected transition.  It’s not a slap in the face. There are few things that are unnerving about this transition, which make it seem markedly different from others: The assumed end of the road for Silverlight is something many think they can see.  Instead of being ignorant of the technology’s expiration date, we believe we know it.  If ignorance is bliss, it would seem our situation lacks it. The new technology involving WinRT and Metro involves a name change from Silverlight. .NET, which underlies both Silverlight and the XAML approach to WinRT development, has just about reached 10 years of age.  That’s equivalent to 80 in human years, or so many fear. My take is that the combination of these three factors has contributed to what for many is a psychologically compelling case that Silverlight should be abandoned today and HTML 5 (the agnostic kind, not the Windows RT variety) should be embraced in its stead.  I understand the logic behind that.  I appreciate the preemptive, proactive, vigilant conscientiousness involved in its calculus.  But for a great many scenarios, I don’t agree with it.  HTML 5 clients, no matter how impressive their interactivity and the emulation of native application interfaces they present may be, are still second-class clients.  They are getting better, especially when hardware acceleration and fast processors are involved.  But they still lag.  They still feel like they’re emulating something, like they’re prototypes, like they’re not comfortable in their own skins.  They are based on compromise, and they feel compromised too. HTML 5/JavaScript development tools are getting better, and will get better still, but they are not as productive as tools for other environments, like Flash, like Silverlight or even more primitive tooling for iOS or Android.  HTML’s roots as a document markup language, rather than an application interface, create a disconnect that impedes productivity.  I do not necessarily think that problem is insurmountable, but it’s here today. If you’re building line-of-business applications, you need a first-class client and you need productivity.  Lack of productivity increases your costs and worsens your backlog.  A second class client will erode user satisfaction, which is never good.  Worse yet, this erosion will be inconspicuous, rather than easily identified and diagnosed, because the inferiority of an HTML 5 client over a native one is hard to identify and, notably, doing so at this juncture in the industry is unpopular.  Why would you fault a technology that everyone believes is revolutionary?  Instead, user disenchantment will remain latent and yet will add to the malaise caused by slower development. If you’re an ISV and you’re coveting the reach of running multi-platform, it’s a different story.  You’ve likely wanted to move to HTML 5 already, and the uncertainty around Silverlight may be the only remaining momentum or pretext you need to make the shift.  You’re deploying many more copies of your application than a line-of-business developer is anyway; this makes the economic hit from lower productivity less impactful, and the wider potential installed base might even make it profitable. But no matter who you are, it’s important to take stock of the situation and do it accurately.  Continued, but merely incremental changes in a development model lead to conservatism and general lack of innovation in the underlying platform.  Periods of stability and equilibrium are necessary, but permanence in that equilibrium leads to loss of platform relevance, market share and utility.  Arguably, that’s already happened to Windows.  The change Windows 8 brings is necessary and overdue.  The marked changes in using .NET if we’re to build applications for the new OS are inevitable.  We will ultimately benefit from the change, and what we can reasonably hope for in the interim is a migration path for our code and skills that is navigable, logical and conceptually comfortable. That path takes us to a place called WinRT, rather than a place called Silverlight.  But considering everything that is changing for the good, the number of disruptive changes is impressively minimal.  The name may be changing, and there may even be some significance to that in terms of Microsoft’s internal management of products and technologies.  But as the consumer, you should care about the ingredients, not the name.  Turkish coffee and Greek coffee are much the same. Although you’ll find plenty of interested parties who will find the names significant, drinkers of the beverage should enjoy either one.  It’s all coffee, it’s all sweet, and you can tell your fortune from the grounds that are left at the end.  Back on the software side, it’s all XAML, and C# or VB .NET, and you can make your fortune from the product that comes out at the end.  Coffee drinkers wouldn’t switch to tea.  Why should XAML developers switch to HTML?

    Read the article

  • Code Measuring and Metrics Tools?

    - by David
    I'm in the process of setting up a build server for personal projects. This server will handle all the normal CI stuff, including running large suites of tests (unit, integration, automated UI). While I'm working out the kinks for including code coverage output with MSTest, it occurs to me that there may be lots of tools out there which give me additional metrics other than just code coverage. FxCop comes to mind as an example. Though I'm sure there are others. Anything that can generate useful reportable data and metrics would be good. Whether it's class dependency charts (looking for Law of Demeter violations, for example), analyses of the uses of classes/functions (looking for a function that isn't used in the system other than just the tests, for example), and so on. I'm not sure the right way to formulate the question, since polling questions or "What's your favorite code analysis tool" aren't very good. But I'm essentially just looking for recommendations on what metrics to gather and the tools that can gather them. The eventual vision for something like this is to have the CI server run a bunch of automated tests and analysis tools and track performance metrics over time. Imagine a dashboard full of graphs plotting these metrics over time. The lines should all relatively be at an equilibrium, and if one starts to stray toward the negative then it's an early indication of problems with the code. In the age old struggle to quantify code quality with management, this sounds like a potentially helpful means of doing just that.

    Read the article

  • Designing a completely new database/gui solution for my compnay

    - by user1277304
    I'm no expert when it come to everything Visual Studio 2010 and utilizing SQL server 2008. I'm sure some of my personal projects I've built for personal use would get laughed off the face of the planet, but SQLCe has been the solution I was looking for those home type of projects. And they work, flawlessly. Now I feel it's time to step up to the big league. I want to develop a complete, unified and module based solution for my company that I'm working for. We're still using stuff from the 80s for goodness sake! I use Excel and query the ancient database on my own because I can't stand the GUI. Nothing against people of age, but the IDE our programmers are using is from the stone age, and they use APL of all things with it. I've yet to see a radio button control anywhere in the GUI where it would make sense. Anyway, I want to do this right from the ground up. I'm by no means a newbie when it comes to programming in .NET 2010, however, I want the entire solution to be professionally done. I want version control, test projects, project flow, SQL 2008 integration and all the bells and whistles that come with that. I know for a fact that if we had something like that running, not only would development costs and time be slashed four fold, but the possibilities for expansion and performance would sky rocket. (Between the GUI an our DB engine, it can only use ONE CORE! ONE! It's 2012 for goodness sake!) Our business is growing and our current ancient solution just can't keep up, and I'd hate to see our business go down in flames because our programmer is stuck in the 80's and refuses to use anything current. So I ask you guys, the experts and know-it-alls, where do I start? Are there any gems of good books out there in the haystack of all "This for dummies" type of deals? I already have several people backing me in this endeavor, and while it may seem brash to just usurp the current programmers, I'm doing this for the company as a whole.

    Read the article

  • Designing a completly new database/gui solution for my compnay

    - by user1277304
    I'm no expert when it come to Everything Visual Studio 2010 and utilizing SQL server 2008. I'm sure some of my personal projects I've built for personal use would get laughed off the face of the planet, but SQLCe has been the solution I was looking for those home type of projects. And they work, flawlessly. Now I feel it's time to step up to the big league. I want to develop a complete, unified and module based solution for my compnay that I'm working for. We're still using stuff from the 80s for goodness sake! I use Excel and query the ancient database on my own because I can't stand the GUI. Nothing against people of age, but the IDE our programmers are using is from the stone age, and they use APL of all things with it. I've yet to see a radio buttton control anywhere in the GUI where it would make sense. Anyway, I want to do this right from the ground up. I'm by no means a newbie when it comes to programming in .NET 2010, however, I want the entire solution to be professionaly done. I want version control, test projects, project flow, SQL 2008 integration and all the bells and whistles that come with that. I know for a fact that if we had something like that runnning, not only would development costs and time be slashed four fold, but the possibilities for expansion and performance would sky rocket. (Between the GUI an our DB engine, it can only use ONE CORE! ONE! It's 2012 for goodness sake!) Our buisness is growing and our current ancient solution just can't keep up, and I'd hate to see our buisness go down in flames because our programmer is stuck in the 80's and refuses to use anything current. So I ask you guys, the experts and know-it-alls, where do I start? Are there any gems of good books out there in the haystack of all "This for dummies" type of deals? I already have several people backing me in this endevour, and while it may seem brash to just usurp the current programmers, I'm doing this for the company as a whole. Thank you guys for your time.

    Read the article

  • How to start a ColorAnimation from a MultiTrigger in a ControlTemplate ?

    - by banzai
    Hi all I have the following ControlTemplate for a WPF TabItem: <ControlTemplate x:Key="DefaultTabItemTemplate" TargetType="{x:Type TabItem}"> <ControlTemplate.Resources> <SolidColorBrush x:Key="UnselectedForegroundBrush" Color="#414141" /> <!-- Unique color for this template --> <SolidColorBrush x:Key="SelectedForegroundBrush" Color="#457581" /> <!-- Unique color for this template --> <SolidColorBrush x:Key="MouseOverTextBrush" x:Name="local_MouseOverTextBrush" Color="#FFF2F2F2"/> </ControlTemplate.Resources> <Grid> <Border Name="Border" MinHeight="30" Margin="0,0,0,-1" Background="{DynamicResource TabControlBackgroundBrush}" BorderBrush="{DynamicResource ndt_DisabledForegroundBrush}" BorderThickness="1,1,1,1" CornerRadius="0,0,0,0" > <ContentPresenter x:Name="ContentSite" VerticalAlignment="Center" HorizontalAlignment="Center" TextElement.FontStretch="UltraExpanded" TextElement.FontWeight="UltraBlack" ContentSource="Header" Margin="12,2,12,2" RecognizesAccessKey="True" /> </Border> </Grid> <ControlTemplate.Triggers> <Trigger Property="IsSelected" Value="True"> <Setter Property="Panel.ZIndex" Value="2" /> <Setter TargetName="Border" Property="Background" Value="{DynamicResource ndt_TabControlBackgroundBrush}" /> <Setter TargetName="Border" Property="BorderThickness" Value="1,1,1,0" /> <Setter TargetName="ContentSite" Property="TextElement.Foreground" Value="{StaticResource SelectedForegroundBrush}" /> </Trigger> <Trigger Property="IsEnabled" Value="False"> <Setter TargetName="Border" Property="Background" Value="{DynamicResource ndt_DisabledBackgroundBrush}" /> <Setter TargetName="ContentSite" Property="TextElement.Foreground" Value="{DynamicResource ndt_DarkGray}" /> <Setter Property="Foreground" Value="{DynamicResource ndt_DisabledForegroundBrush}" /> </Trigger> <MultiTrigger> <MultiTrigger.Conditions> <Condition Property="IsMouseOver" Value="True" /> <Condition Property="IsSelected" Value="False" /> </MultiTrigger.Conditions> <Setter TargetName="Border" Property="Background" Value="{DynamicResource ndt_NavigationAreaBrush}" /> <Setter TargetName="ContentSite" Property="TextElement.Foreground" Value="{DynamicResource MouseOverTextBrush}" /> </MultiTrigger> </ControlTemplate.Triggers> </ControlTemplate> Everything works fine so far. The MultiTrigger at the end of the template defines a mouse over effect for not selected TabItems. Now I thought the change in color for this mouse over effect looks a bit brash so let´s animate it with a ColorAnimation. But don´t count the chickens before they hatch - everything I tried didn´t work. Maybe I oversee the obvious - but how to achieve this feat ? Thanks in advance banzai

    Read the article

  • Since upgrading to Solaris 11, my ARC size has consistently targeted 119MB, despite having 30GB RAM. What? Why?

    - by growse
    I ran a NAS/SAN box on Solaris 11 Express before Solaris 11 was released. The box is an HP X1600 with an attached D2700. In all, 12x 1TB 7200 SATA disks, 12x 300GB 10k SAS disks in separate zpools. Total RAM is 30GB. Services provided are CIFS, NFS and iSCSI. All was well, and I had a ZFS memory usage graph looking like this: A fairly healthy Arc size of around 23GB - making use of the available memory for caching. However, I then upgraded to Solaris 11 when that came out. Now, my graph looks like this: Partial output of arc_summary.pl is: System Memory: Physical RAM: 30701 MB Free Memory : 26719 MB LotsFree: 479 MB ZFS Tunables (/etc/system): ARC Size: Current Size: 915 MB (arcsize) Target Size (Adaptive): 119 MB (c) Min Size (Hard Limit): 64 MB (zfs_arc_min) Max Size (Hard Limit): 29677 MB (zfs_arc_max) It's targetting 119MB while sitting at 915MB. It's got 30GB to play with. Why? Did they change something? Edit To clarify, arc_summary.pl is Ben Rockwood's, and the relevent lines generating the above stats are: my $mru_size = ${Kstat}->{zfs}->{0}->{arcstats}->{p}; my $target_size = ${Kstat}->{zfs}->{0}->{arcstats}->{c}; my $arc_min_size = ${Kstat}->{zfs}->{0}->{arcstats}->{c_min}; my $arc_max_size = ${Kstat}->{zfs}->{0}->{arcstats}->{c_max}; my $arc_size = ${Kstat}->{zfs}->{0}->{arcstats}->{size}; The Kstat entries are there, I'm just getting odd values out of them. Edit 2 I've just re-measured the arc size with arc_summary.pl - I've verified these numbers with kstat: System Memory: Physical RAM: 30701 MB Free Memory : 26697 MB LotsFree: 479 MB ZFS Tunables (/etc/system): ARC Size: Current Size: 744 MB (arcsize) Target Size (Adaptive): 119 MB (c) Min Size (Hard Limit): 64 MB (zfs_arc_min) Max Size (Hard Limit): 29677 MB (zfs_arc_max) The thing that strikes me is that the Target Size is 119MB. Looking at the graph, it's targeted the exact same value (124.91M according to cacti, 119M according to arc_summary.pl - think the difference is just 1024/1000 rounding issues) ever since Solaris 11 was installed. It looks like the kernel's making zero effort to shift the target size to anything different. The current size is fluctuating as the needs of the system (large) fight with the target size, and it appears equilibrium is between 700 and 1000MB. So the question is now a little more pointed - why is Solaris 11 hard setting my ARC target size to 119MB, and how do I change it? Should I raise the min size to see what happens? I've stuck the output of kstat -n arcstats over at http://pastebin.com/WHPimhfg Edit 3 Ok, weirdness now. I know flibflob mentioned that there was a patch to fix this. I haven't applied this patch yet (still sorting out internal support issues) and I've not applied any other software updates. Last thursday, the box crashed. As in, completely stopped responding to everything. When I rebooted it, it came back up fine, but here's what my graph now looks like. It seems to have fixed the problem. This is proper la la land stuff now. I've literally no idea what's going on. :(

    Read the article

1