Search Results

Search found 1776 results on 72 pages for 'cached'.

Page 20/72 | < Previous Page | 16 17 18 19 20 21 22 23 24 25 26 27  | Next Page >

  • Velocity CTP: can we 'search' for objects?

    - by Stato Machino
    It appears that 'tags' allow us to associate a 'search term' with the objects placed into the Velocity cache space. However, these can only be queried within a 'region'. Further, regions somehow limit the locality of objects in the cache to a single server (or maybe something kinda like that). So this appears to make it hard to perform any operation for which the unique Id of the cached item is not persisted or continuously available to the application that stores and retrieves objects to and from the cache. In any case, I can't see an easy way to 'cleanse' the cache of objects or to find objects across the entire cache that may share some prefix, postfix or infix values in the cache key so that i can clear out the cache of object repeatedly created in unit tests, for example. And I am unsure about the consequences of regions being associated with single server cache locations. So I would appreciate any help with the following questions: What is the difference between a 'distributed cache' (called a 'partitioned' cache??) when using regions, and a 'local cache'? 1.a. In particular, are the region-oriented values in a distributed cache visible through a cache factory that is configured to 'see' the entire cache space? Are the operations of creating and removing 'regions' efficient enough that it would be reasonable to create a region and a group of tags for each bundle of objects that need to be cached? 2.a. Or does this just push the problem of scoping the 'search for objects' up the chain because the ability of the DataCache object to query down through regions and tags as limited as querying for the cache keys of objects themselves. Thanks, Stato

    Read the article

  • What are good design practices when working with Entity Framework

    - by AD
    This will apply mostly for an asp.net application where the data is not accessed via soa. Meaning that you get access to the objects loaded from the framework, not Transfer Objects, although some recommendation still apply. This is a community post, so please add to it as you see fit. Applies to: Entity Framework 1.0 shipped with Visual Studio 2008 sp1. Why pick EF in the first place? Considering it is a young technology with plenty of problems (see below), it may be a hard sell to get on the EF bandwagon for your project. However, it is the technology Microsoft is pushing (at the expense of Linq2Sql, which is a subset of EF). In addition, you may not be satisfied with NHibernate or other solutions out there. Whatever the reasons, there are people out there (including me) working with EF and life is not bad.make you think. EF and inheritance The first big subject is inheritance. EF does support mapping for inherited classes that are persisted in 2 ways: table per class and table the hierarchy. The modeling is easy and there are no programming issues with that part. (The following applies to table per class model as I don't have experience with table per hierarchy, which is, anyway, limited.) The real problem comes when you are trying to run queries that include one or many objects that are part of an inheritance tree: the generated sql is incredibly awful, takes a long time to get parsed by the EF and takes a long time to execute as well. This is a real show stopper. Enough that EF should probably not be used with inheritance or as little as possible. Here is an example of how bad it was. My EF model had ~30 classes, ~10 of which were part of an inheritance tree. On running a query to get one item from the Base class, something as simple as Base.Get(id), the generated SQL was over 50,000 characters. Then when you are trying to return some Associations, it degenerates even more, going as far as throwing SQL exceptions about not being able to query more than 256 tables at once. Ok, this is bad, EF concept is to allow you to create your object structure without (or with as little as possible) consideration on the actual database implementation of your table. It completely fails at this. So, recommendations? Avoid inheritance if you can, the performance will be so much better. Use it sparingly where you have to. In my opinion, this makes EF a glorified sql-generation tool for querying, but there are still advantages to using it. And ways to implement mechanism that are similar to inheritance. Bypassing inheritance with Interfaces First thing to know with trying to get some kind of inheritance going with EF is that you cannot assign a non-EF-modeled class a base class. Don't even try it, it will get overwritten by the modeler. So what to do? You can use interfaces to enforce that classes implement some functionality. For example here is a IEntity interface that allow you to define Associations between EF entities where you don't know at design time what the type of the entity would be. public enum EntityTypes{ Unknown = -1, Dog = 0, Cat } public interface IEntity { int EntityID { get; } string Name { get; } Type EntityType { get; } } public partial class Dog : IEntity { // implement EntityID and Name which could actually be fields // from your EF model Type EntityType{ get{ return EntityTypes.Dog; } } } Using this IEntity, you can then work with undefined associations in other classes // lets take a class that you defined in your model. // that class has a mapping to the columns: PetID, PetType public partial class Person { public IEntity GetPet() { return IEntityController.Get(PetID,PetType); } } which makes use of some extension functions: public class IEntityController { static public IEntity Get(int id, EntityTypes type) { switch (type) { case EntityTypes.Dog: return Dog.Get(id); case EntityTypes.Cat: return Cat.Get(id); default: throw new Exception("Invalid EntityType"); } } } Not as neat as having plain inheritance, particularly considering you have to store the PetType in an extra database field, but considering the performance gains, I would not look back. It also cannot model one-to-many, many-to-many relationship, but with creative uses of 'Union' it could be made to work. Finally, it creates the side effet of loading data in a property/function of the object, which you need to be careful about. Using a clear naming convention like GetXYZ() helps in that regards. Compiled Queries Entity Framework performance is not as good as direct database access with ADO (obviously) or Linq2SQL. There are ways to improve it however, one of which is compiling your queries. The performance of a compiled query is similar to Linq2Sql. What is a compiled query? It is simply a query for which you tell the framework to keep the parsed tree in memory so it doesn't need to be regenerated the next time you run it. So the next run, you will save the time it takes to parse the tree. Do not discount that as it is a very costly operation that gets even worse with more complex queries. There are 2 ways to compile a query: creating an ObjectQuery with EntitySQL and using CompiledQuery.Compile() function. (Note that by using an EntityDataSource in your page, you will in fact be using ObjectQuery with EntitySQL, so that gets compiled and cached). An aside here in case you don't know what EntitySQL is. It is a string-based way of writing queries against the EF. Here is an example: "select value dog from Entities.DogSet as dog where dog.ID = @ID". The syntax is pretty similar to SQL syntax. You can also do pretty complex object manipulation, which is well explained [here][1]. Ok, so here is how to do it using ObjectQuery< string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); The first time you run this query, the framework will generate the expression tree and keep it in memory. So the next time it gets executed, you will save on that costly step. In that example EnablePlanCaching = true, which is unnecessary since that is the default option. The other way to compile a query for later use is the CompiledQuery.Compile method. This uses a delegate: static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => ctx.DogSet.FirstOrDefault(it => it.ID == id)); or using linq static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet where dog.ID == id select dog).FirstOrDefault()); to call the query: query_GetDog.Invoke( YourContext, id ); The advantage of CompiledQuery is that the syntax of your query is checked at compile time, where as EntitySQL is not. However, there are other consideration... Includes Lets say you want to have the data for the dog owner to be returned by the query to avoid making 2 calls to the database. Easy to do, right? EntitySQL string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)).Include("Owner"); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); CompiledQuery static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet.Include("Owner") where dog.ID == id select dog).FirstOrDefault()); Now, what if you want to have the Include parametrized? What I mean is that you want to have a single Get() function that is called from different pages that care about different relationships for the dog. One cares about the Owner, another about his FavoriteFood, another about his FavotireToy and so on. Basicly, you want to tell the query which associations to load. It is easy to do with EntitySQL public Dog Get(int id, string include) { string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)) .IncludeMany(include); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); } The include simply uses the passed string. Easy enough. Note that it is possible to improve on the Include(string) function (that accepts only a single path) with an IncludeMany(string) that will let you pass a string of comma-separated associations to load. Look further in the extension section for this function. If we try to do it with CompiledQuery however, we run into numerous problems: The obvious static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.Include(include) where dog.ID == id select dog).FirstOrDefault()); will choke when called with: query_GetDog.Invoke( YourContext, id, "Owner,FavoriteFood" ); Because, as mentionned above, Include() only wants to see a single path in the string and here we are giving it 2: "Owner" and "FavoriteFood" (which is not to be confused with "Owner.FavoriteFood"!). Then, let's use IncludeMany(), which is an extension function static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.IncludeMany(include) where dog.ID == id select dog).FirstOrDefault()); Wrong again, this time it is because the EF cannot parse IncludeMany because it is not part of the functions that is recognizes: it is an extension. Ok, so you want to pass an arbitrary number of paths to your function and Includes() only takes a single one. What to do? You could decide that you will never ever need more than, say 20 Includes, and pass each separated strings in a struct to CompiledQuery. But now the query looks like this: from dog in ctx.DogSet.Include(include1).Include(include2).Include(include3) .Include(include4).Include(include5).Include(include6) .[...].Include(include19).Include(include20) where dog.ID == id select dog which is awful as well. Ok, then, but wait a minute. Can't we return an ObjectQuery< with CompiledQuery? Then set the includes on that? Well, that what I would have thought so as well: static readonly Func<Entities, int, ObjectQuery<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, ObjectQuery<Dog>>((ctx, id) => (ObjectQuery<Dog>)(from dog in ctx.DogSet where dog.ID == id select dog)); public Dog GetDog( int id, string include ) { ObjectQuery<Dog> oQuery = query_GetDog(id); oQuery = oQuery.IncludeMany(include); return oQuery.FirstOrDefault; } That should have worked, except that when you call IncludeMany (or Include, Where, OrderBy...) you invalidate the cached compiled query because it is an entirely new one now! So, the expression tree needs to be reparsed and you get that performance hit again. So what is the solution? You simply cannot use CompiledQueries with parametrized Includes. Use EntitySQL instead. This doesn't mean that there aren't uses for CompiledQueries. It is great for localized queries that will always be called in the same context. Ideally CompiledQuery should always be used because the syntax is checked at compile time, but due to limitation, that's not possible. An example of use would be: you may want to have a page that queries which two dogs have the same favorite food, which is a bit narrow for a BusinessLayer function, so you put it in your page and know exactly what type of includes are required. Passing more than 3 parameters to a CompiledQuery Func is limited to 5 parameters, of which the last one is the return type and the first one is your Entities object from the model. So that leaves you with 3 parameters. A pitance, but it can be improved on very easily. public struct MyParams { public string param1; public int param2; public DateTime param3; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where dog.Age == myParams.param2 && dog.Name == myParams.param1 and dog.BirthDate > myParams.param3 select dog); public List<Dog> GetSomeDogs( int age, string Name, DateTime birthDate ) { MyParams myParams = new MyParams(); myParams.param1 = name; myParams.param2 = age; myParams.param3 = birthDate; return query_GetDog(YourContext,myParams).ToList(); } Return Types (this does not apply to EntitySQL queries as they aren't compiled at the same time during execution as the CompiledQuery method) Working with Linq, you usually don't force the execution of the query until the very last moment, in case some other functions downstream wants to change the query in some way: static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public IEnumerable<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name); } public void DataBindStuff() { IEnumerable<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } What is going to happen here? By still playing with the original ObjectQuery (that is the actual return type of the Linq statement, which implements IEnumerable), it will invalidate the compiled query and be force to re-parse. So, the rule of thumb is to return a List< of objects instead. static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public List<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name).ToList(); //<== change here } public void DataBindStuff() { List<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } When you call ToList(), the query gets executed as per the compiled query and then, later, the OrderBy is executed against the objects in memory. It may be a little bit slower, but I'm not even sure. One sure thing is that you have no worries about mis-handling the ObjectQuery and invalidating the compiled query plan. Once again, that is not a blanket statement. ToList() is a defensive programming trick, but if you have a valid reason not to use ToList(), go ahead. There are many cases in which you would want to refine the query before executing it. Performance What is the performance impact of compiling a query? It can actually be fairly large. A rule of thumb is that compiling and caching the query for reuse takes at least double the time of simply executing it without caching. For complex queries (read inherirante), I have seen upwards to 10 seconds. So, the first time a pre-compiled query gets called, you get a performance hit. After that first hit, performance is noticeably better than the same non-pre-compiled query. Practically the same as Linq2Sql When you load a page with pre-compiled queries the first time you will get a hit. It will load in maybe 5-15 seconds (obviously more than one pre-compiled queries will end up being called), while subsequent loads will take less than 300ms. Dramatic difference, and it is up to you to decide if it is ok for your first user to take a hit or you want a script to call your pages to force a compilation of the queries. Can this query be cached? { Dog dog = from dog in YourContext.DogSet where dog.ID == id select dog; } No, ad-hoc Linq queries are not cached and you will incur the cost of generating the tree every single time you call it. Parametrized Queries Most search capabilities involve heavily parametrized queries. There are even libraries available that will let you build a parametrized query out of lamba expressions. The problem is that you cannot use pre-compiled queries with those. One way around that is to map out all the possible criteria in the query and flag which one you want to use: public struct MyParams { public string name; public bool checkName; public int age; public bool checkAge; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where (myParams.checkAge == true && dog.Age == myParams.age) && (myParams.checkName == true && dog.Name == myParams.name ) select dog); protected List<Dog> GetSomeDogs() { MyParams myParams = new MyParams(); myParams.name = "Bud"; myParams.checkName = true; myParams.age = 0; myParams.checkAge = false; return query_GetDog(YourContext,myParams).ToList(); } The advantage here is that you get all the benifits of a pre-compiled quert. The disadvantages are that you most likely will end up with a where clause that is pretty difficult to maintain, that you will incur a bigger penalty for pre-compiling the query and that each query you run is not as efficient as it could be (particularly with joins thrown in). Another way is to build an EntitySQL query piece by piece, like we all did with SQL. protected List<Dod> GetSomeDogs( string name, int age) { string query = "select value dog from Entities.DogSet where 1 = 1 "; if( !String.IsNullOrEmpty(name) ) query = query + " and dog.Name == @Name "; if( age > 0 ) query = query + " and dog.Age == @Age "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); if( !String.IsNullOrEmpty(name) ) oQuery.Parameters.Add( new ObjectParameter( "Name", name ) ); if( age > 0 ) oQuery.Parameters.Add( new ObjectParameter( "Age", age ) ); return oQuery.ToList(); } Here the problems are: - there is no syntax checking during compilation - each different combination of parameters generate a different query which will need to be pre-compiled when it is first run. In this case, there are only 4 different possible queries (no params, age-only, name-only and both params), but you can see that there can be way more with a normal world search. - Noone likes to concatenate strings! Another option is to query a large subset of the data and then narrow it down in memory. This is particularly useful if you are working with a definite subset of the data, like all the dogs in a city. You know there are a lot but you also know there aren't that many... so your CityDog search page can load all the dogs for the city in memory, which is a single pre-compiled query and then refine the results protected List<Dod> GetSomeDogs( string name, int age, string city) { string query = "select value dog from Entities.DogSet where dog.Owner.Address.City == @City "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); oQuery.Parameters.Add( new ObjectParameter( "City", city ) ); List<Dog> dogs = oQuery.ToList(); if( !String.IsNullOrEmpty(name) ) dogs = dogs.Where( it => it.Name == name ); if( age > 0 ) dogs = dogs.Where( it => it.Age == age ); return dogs; } It is particularly useful when you start displaying all the data then allow for filtering. Problems: - Could lead to serious data transfer if you are not careful about your subset. - You can only filter on the data that you returned. It means that if you don't return the Dog.Owner association, you will not be able to filter on the Dog.Owner.Name So what is the best solution? There isn't any. You need to pick the solution that works best for you and your problem: - Use lambda-based query building when you don't care about pre-compiling your queries. - Use fully-defined pre-compiled Linq query when your object structure is not too complex. - Use EntitySQL/string concatenation when the structure could be complex and when the possible number of different resulting queries are small (which means fewer pre-compilation hits). - Use in-memory filtering when you are working with a smallish subset of the data or when you had to fetch all of the data on the data at first anyway (if the performance is fine with all the data, then filtering in memory will not cause any time to be spent in the db). Singleton access The best way to deal with your context and entities accross all your pages is to use the singleton pattern: public sealed class YourContext { private const string instanceKey = "On3GoModelKey"; YourContext(){} public static YourEntities Instance { get { HttpContext context = HttpContext.Current; if( context == null ) return Nested.instance; if (context.Items[instanceKey] == null) { On3GoEntities entity = new On3GoEntities(); context.Items[instanceKey] = entity; } return (YourEntities)context.Items[instanceKey]; } } class Nested { // Explicit static constructor to tell C# compiler // not to mark type as beforefieldinit static Nested() { } internal static readonly YourEntities instance = new YourEntities(); } } NoTracking, is it worth it? When executing a query, you can tell the framework to track the objects it will return or not. What does it mean? With tracking enabled (the default option), the framework will track what is going on with the object (has it been modified? Created? Deleted?) and will also link objects together, when further queries are made from the database, which is what is of interest here. For example, lets assume that Dog with ID == 2 has an owner which ID == 10. Dog dog = (from dog in YourContext.DogSet where dog.ID == 2 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Person owner = (from o in YourContext.PersonSet where o.ID == 10 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == true; If we were to do the same with no tracking, the result would be different. ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog = oDogQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>) (from o in YourContext.PersonSet where o.ID == 10 select o); oPersonQuery.MergeOption = MergeOption.NoTracking; Owner owner = oPersonQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Tracking is very useful and in a perfect world without performance issue, it would always be on. But in this world, there is a price for it, in terms of performance. So, should you use NoTracking to speed things up? It depends on what you are planning to use the data for. Is there any chance that the data your query with NoTracking can be used to make update/insert/delete in the database? If so, don't use NoTracking because associations are not tracked and will causes exceptions to be thrown. In a page where there are absolutly no updates to the database, you can use NoTracking. Mixing tracking and NoTracking is possible, but it requires you to be extra careful with updates/inserts/deletes. The problem is that if you mix then you risk having the framework trying to Attach() a NoTracking object to the context where another copy of the same object exist with tracking on. Basicly, what I am saying is that Dog dog1 = (from dog in YourContext.DogSet where dog.ID == 2).FirstOrDefault(); ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog2 = oDogQuery.FirstOrDefault(); dog1 and dog2 are 2 different objects, one tracked and one not. Using the detached object in an update/insert will force an Attach() that will say "Wait a minute, I do already have an object here with the same database key. Fail". And when you Attach() one object, all of its hierarchy gets attached as well, causing problems everywhere. Be extra careful. How much faster is it with NoTracking It depends on the queries. Some are much more succeptible to tracking than other. I don't have a fast an easy rule for it, but it helps. So I should use NoTracking everywhere then? Not exactly. There are some advantages to tracking object. The first one is that the object is cached, so subsequent call for that object will not hit the database. That cache is only valid for the lifetime of the YourEntities object, which, if you use the singleton code above, is the same as the page lifetime. One page request == one YourEntity object. So for multiple calls for the same object, it will load only once per page request. (Other caching mechanism could extend that). What happens when you are using NoTracking and try to load the same object multiple times? The database will be queried each time, so there is an impact there. How often do/should you call for the same object during a single page request? As little as possible of course, but it does happens. Also remember the piece above about having the associations connected automatically for your? You don't have that with NoTracking, so if you load your data in multiple batches, you will not have a link to between them: ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>)(from dog in YourContext.DogSet select dog); oDogQuery.MergeOption = MergeOption.NoTracking; List<Dog> dogs = oDogQuery.ToList(); ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>)(from o in YourContext.PersonSet select o); oPersonQuery.MergeOption = MergeOption.NoTracking; List<Person> owners = oPersonQuery.ToList(); In this case, no dog will have its .Owner property set. Some things to keep in mind when you are trying to optimize the performance. No lazy loading, what am I to do? This can be seen as a blessing in disguise. Of course it is annoying to load everything manually. However, it decreases the number of calls to the db and forces you to think about when you should load data. The more you can load in one database call the better. That was always true, but it is enforced now with this 'feature' of EF. Of course, you can call if( !ObjectReference.IsLoaded ) ObjectReference.Load(); if you want to, but a better practice is to force the framework to load the objects you know you will need in one shot. This is where the discussion about parametrized Includes begins to make sense. Lets say you have you Dog object public class Dog { public Dog Get(int id) { return YourContext.DogSet.FirstOrDefault(it => it.ID == id ); } } This is the type of function you work with all the time. It gets called from all over the place and once you have that Dog object, you will do very different things to it in different functions. First, it should be pre-compiled, because you will call that very often. Second, each different pages will want to have access to a different subset of the Dog data. Some will want the Owner, some the FavoriteToy, etc. Of course, you could call Load() for each reference you need anytime you need one. But that will generate a call to the database each time. Bad idea. So instead, each page will ask for the data it wants to see when it first request for the Dog object: static public Dog Get(int id) { return GetDog(entity,"");} static public Dog Get(int id, string includePath) { string query = "select value o " + " from YourEntities.DogSet as o " +

    Read the article

  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

    - by Tarun Arora
    Welcome back once again, in Part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies, in Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

    Read the article

  • Why won't xattr PECL extension build on 12.10?

    - by Dan Jones
    I was using the xattr pecl extension in 12.04 (in fact, I think since 10.04) without problem. Not surprisingly, I had to reinstall it after upgrading to 12.10 because of the new version of PHP. But now it fails to build, and I can't figure out why. Other PECL extensions have built fine. And I have libattr1 and libattr1-dev installed. Here's the output from the build: downloading xattr-1.1.0.tgz ... Starting to download xattr-1.1.0.tgz (5,204 bytes) .....done: 5,204 bytes 3 source files, building running: phpize Configuring for: PHP Api Version: 20100412 Zend Module Api No: 20100525 Zend Extension Api No: 220100525 libattr library installation dir? [autodetect] : building in /tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0 running: /tmp/pear/temp/xattr/configure --with-xattr checking for grep that handles long lines and -e... /bin/grep checking for egrep... /bin/grep -E checking for a sed that does not truncate output... /bin/sed checking for cc... cc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether cc accepts -g... yes checking for cc option to accept ISO C89... none needed checking how to run the C preprocessor... cc -E checking for icc... no checking for suncc... no checking whether cc understands -c and -o together... yes checking for system library directory... lib checking if compiler supports -R... no checking if compiler supports -Wl,-rpath,... yes checking build system type... x86_64-unknown-linux-gnu checking host system type... x86_64-unknown-linux-gnu checking target system type... x86_64-unknown-linux-gnu checking for PHP prefix... /usr checking for PHP includes... -I/usr/include/php5 -I/usr/include/php5/main -I/usr/include/php5/TSRM -I/usr/include/php5/Zend -I/usr/include/php5/ext -I/usr/include/php5/ext/date/lib checking for PHP extension directory... /usr/lib/php5/20100525 checking for PHP installed headers prefix... /usr/include/php5 checking if debug is enabled... no checking if zts is enabled... no checking for re2c... re2c checking for re2c version... 0.13.5 (ok) checking for gawk... gawk checking for xattr support... yes, shared checking for xattr files in default path... found in /usr checking for attr_get in -lattr... yes checking how to print strings... printf checking for a sed that does not truncate output... (cached) /bin/sed checking for fgrep... /bin/grep -F checking for ld used by cc... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B checking the name lister (/usr/bin/nm -B) interface... BSD nm checking whether ln -s works... yes checking the maximum length of command line arguments... 1572864 checking whether the shell understands some XSI constructs... yes checking whether the shell understands "+="... yes checking how to convert x86_64-unknown-linux-gnu file names to x86_64-unknown-linux-gnu format... func_convert_file_noop checking how to convert x86_64-unknown-linux-gnu file names to toolchain format... func_convert_file_noop checking for /usr/bin/ld option to reload object files... -r checking for objdump... objdump checking how to recognize dependent libraries... pass_all checking for dlltool... no checking how to associate runtime and link libraries... printf %s\n checking for ar... ar checking for archiver @FILE support... @ checking for strip... strip checking for ranlib... ranlib checking for gawk... (cached) gawk checking command to parse /usr/bin/nm -B output from cc object... ok checking for sysroot... no checking for mt... mt checking if mt is a manifest tool... no checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking for dlfcn.h... yes checking for objdir... .libs checking if cc supports -fno-rtti -fno-exceptions... no checking for cc option to produce PIC... -fPIC -DPIC checking if cc PIC flag -fPIC -DPIC works... yes checking if cc static flag -static works... yes checking if cc supports -c -o file.o... yes checking if cc supports -c -o file.o... (cached) yes checking whether the cc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... no configure: creating ./config.status config.status: creating config.h config.status: executing libtool commands running: make /bin/bash /tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0/libtool --mode=compile cc -I. -I/tmp/pear/temp/xattr -DPHP_ATOM_INC -I/tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0/include -I/tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0/main -I/tmp/pear/temp/xattr -I/usr/include/php5 -I/usr/include/php5/main -I/usr/include/php5/TSRM -I/usr/include/php5/Zend -I/usr/include/php5/ext -I/usr/include/php5/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /tmp/pear/temp/xattr/xattr.c -o xattr.lo libtool: compile: cc -I. -I/tmp/pear/temp/xattr -DPHP_ATOM_INC -I/tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0/include -I/tmp/pear/temp/pear-build-rootdSMx0G/xattr-1.1.0/main -I/tmp/pear/temp/xattr -I/usr/include/php5 -I/usr/include/php5/main -I/usr/include/php5/TSRM -I/usr/include/php5/Zend -I/usr/include/php5/ext -I/usr/include/php5/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /tmp/pear/temp/xattr/xattr.c -fPIC -DPIC -o .libs/xattr.o /tmp/pear/temp/xattr/xattr.c:50:1: error: unknown type name 'function_entry' /tmp/pear/temp/xattr/xattr.c:51:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: error: initializer element is not computable at load time /tmp/pear/temp/xattr/xattr.c:51:2: error: (near initialization for 'xattr_functions[0]') /tmp/pear/temp/xattr/xattr.c:51:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:51:2: warning: (near initialization for 'xattr_functions[0]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: error: initializer element is not computable at load time /tmp/pear/temp/xattr/xattr.c:52:2: error: (near initialization for 'xattr_functions[1]') /tmp/pear/temp/xattr/xattr.c:52:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:52:2: warning: (near initialization for 'xattr_functions[1]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: error: initializer element is not computable at load time /tmp/pear/temp/xattr/xattr.c:53:2: error: (near initialization for 'xattr_functions[2]') /tmp/pear/temp/xattr/xattr.c:53:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:53:2: warning: (near initialization for 'xattr_functions[2]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: error: initializer element is not computable at load time /tmp/pear/temp/xattr/xattr.c:54:2: error: (near initialization for 'xattr_functions[3]') /tmp/pear/temp/xattr/xattr.c:54:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:54:2: warning: (near initialization for 'xattr_functions[3]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: error: initializer element is not computable at load time /tmp/pear/temp/xattr/xattr.c:55:2: error: (near initialization for 'xattr_functions[4]') /tmp/pear/temp/xattr/xattr.c:55:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:55:2: warning: (near initialization for 'xattr_functions[4]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: braces around scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: (near initialization for 'xattr_functions[5]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: initialization makes integer from pointer without a cast [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: (near initialization for 'xattr_functions[5]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: (near initialization for 'xattr_functions[5]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: excess elements in scalar initializer [enabled by default] /tmp/pear/temp/xattr/xattr.c:56:2: warning: (near initialization for 'xattr_functions[5]') [enabled by default] /tmp/pear/temp/xattr/xattr.c:67:2: warning: initialization from incompatible pointer type [enabled by default] /tmp/pear/temp/xattr/xattr.c:67:2: warning: (near initialization for 'xattr_module_entry.functions') [enabled by default] /tmp/pear/temp/xattr/xattr.c: In function 'zif_xattr_set': /tmp/pear/temp/xattr/xattr.c:122:49: error: 'struct _php_core_globals' has no member named 'safe_mode' /tmp/pear/temp/xattr/xattr.c:122:92: error: 'CHECKUID_DISALLOW_FILE_NOT_EXISTS' undeclared (first use in this function) /tmp/pear/temp/xattr/xattr.c:122:92: note: each undeclared identifier is reported only once for each function it appears in /tmp/pear/temp/xattr/xattr.c: In function 'zif_xattr_get': /tmp/pear/temp/xattr/xattr.c:171:49: error: 'struct _php_core_globals' has no member named 'safe_mode' /tmp/pear/temp/xattr/xattr.c:171:92: error: 'CHECKUID_DISALLOW_FILE_NOT_EXISTS' undeclared (first use in this function) /tmp/pear/temp/xattr/xattr.c:187:2: warning: passing argument 4 of 'attr_get' from incompatible pointer type [enabled by default] In file included from /tmp/pear/temp/xattr/xattr.c:37:0: /usr/include/attr/attributes.h:122:12: note: expected 'int *' but argument is of type 'size_t *' /tmp/pear/temp/xattr/xattr.c:198:3: warning: passing argument 4 of 'attr_get' from incompatible pointer type [enabled by default] In file included from /tmp/pear/temp/xattr/xattr.c:37:0: /usr/include/attr/attributes.h:122:12: note: expected 'int *' but argument is of type 'size_t *' /tmp/pear/temp/xattr/xattr.c: In function 'zif_xattr_supported': /tmp/pear/temp/xattr/xattr.c:243:49: error: 'struct _php_core_globals' has no member named 'safe_mode' /tmp/pear/temp/xattr/xattr.c:243:92: error: 'CHECKUID_DISALLOW_FILE_NOT_EXISTS' undeclared (first use in this function) /tmp/pear/temp/xattr/xattr.c: In function 'zif_xattr_remove': /tmp/pear/temp/xattr/xattr.c:288:49: error: 'struct _php_core_globals' has no member named 'safe_mode' /tmp/pear/temp/xattr/xattr.c:288:92: error: 'CHECKUID_DISALLOW_FILE_NOT_EXISTS' undeclared (first use in this function) /tmp/pear/temp/xattr/xattr.c: In function 'zif_xattr_list': /tmp/pear/temp/xattr/xattr.c:337:49: error: 'struct _php_core_globals' has no member named 'safe_mode' /tmp/pear/temp/xattr/xattr.c:337:92: error: 'CHECKUID_DISALLOW_FILE_NOT_EXISTS' undeclared (first use in this function) make: *** [xattr.lo] Error 1 ERROR: `make' failed There seem to be a few errors, but I can't make heads or tails of them. Does this just not work properly in 12.10? That would be a big problem for me.

    Read the article

  • Installing gitweb failed: No package gitweb available

    - by logii
    I have tried installing gitweb via ssh and failed. Below is what I get. root@server [~]# yum install gitweb Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: ftp-stud.fht-esslingen.de rpmforge | 1.1 kB 00:00 rpmforge/primary | 3.8 MB 00:19 rpmforge 10502/10502 Excluding Packages in global exclude list Finished Setting up Install Process No package gitweb available. Nothing to do Anyone has any idea of what else is missing?

    Read the article

  • Why isn´t linux using all the available memory

    - by Devator
    I have a linux VPS which has 256 MB of memory (free only finds 248 though). However it seems I still have 85 MB free, but it's swapping for 255 MB. Why is this? free -m total used free shared buffers cached Mem: 248 245 3 0 41 40 -/+ buffers/cache: 163 85 Swap: 1971 255 1716

    Read the article

  • Change password via NetScreen remote

    - by Marcelo Cantos
    I'm using NetScreen remote to VPN from home. I recently changed my password at work, and now my home system keeps complaining, "Windows needs your current credentials to ensure network connectivity." I can't change the cached password for peanuts. I can't find an option in NetScreen remote to connect to the VPN before logging in, as suggested here.

    Read the article

  • Installing VLC on CentOS 6.2

    - by suraj
    I'm using CentOS 6.2, and I tried to install VLC Player using yum, but it shows "No package vlc available". I tried below command: [root@localhost ~]# yum install vlc Loaded plugins: fastestmirror, refresh-packagekit Loading mirror speeds from cached hostfile * base: ftp.iitm.ac.in * extras: ftp.iitm.ac.in * updates: ftp.iitm.ac.in base | 3.7 kB 00:00 extras | 3.5 kB 00:00 updates | 3.5 kB 00:00 updates/primary_db | 3.4 MB 01:17 virtualbox | 951 B 00:00 Setting up Install Process No package vlc available. Error: Nothing to do Is there any rpm package available?

    Read the article

  • Nginx: Can I cache a URL matching a pattern at a different URL?

    - by Josh French
    I have a site with some URLs that look like this: /prefix/ID, where /prefix is static and ID is unique. Using Nginx as a reverse proxy, I'd like to cache these pages at the /ID portion only, omitting the prefix. Can I configure Nginx so that a request for the original URL is cached at the shortened URL? I tried this (I'm omitting some irrelevant parts) but obviously it's not the correct solution: http { map $request_uri $page_id { default $request_uri; ~^/prefix/(?<id>.+)$ $id; } location / { proxy_cache_key $page_id } }

    Read the article

  • APC (PHP Cache) Uptime 0 minutes, not caching

    - by Jussi
    My goal is to implement APC for opcode cache for a drupal 6 production site. I have so far tested APC with several php files with and without including other php files with include_once. Also tried to tweak the apc.ini values for shm_size, apc.include_once_override and apc.stat. Restarted apache every time. Resulting in apc.php not showing any changes in any values. (except of course the changed apc.ini values are shown as they should) Every time i refresh the apc.php test page, the start time resets as the current time showing uptime 0 minutes. apc.php -testpage shows: General Cache InformationAPC Version 3.1.9 PHP Version 5.2.10 APC Host xxxx.xx.xx Server Software Apache/2.2.3 (CentOS) Shared Memory 1 Segment(s) with 128.0 MBytes (mmap memory, pthread mutex Locks locking) Start Time 2011/07/26 11:53:56 Uptime 0 minutes File Upload Support 1 Cached Files 0 ( 0.0 Bytes) Hits 1 Misses 1 Request Rate (hits, misses) 2.00 cache requests/second Hit Rate 1.00 cache requests/second Miss Rate 1.00 cache requests/second Insert Rate 0.00 cache requests/second Cache full count 0 Cached Variables 0 ( 0.0 Bytes) Hits 0 Misses 0 Request Rate (hits, misses) 0.00 cache requests/second Hit Rate 0.00 cache requests/second Miss Rate 0.00 cache requests/second Insert Rate 0.00 cache requests/second Cache full count 0 apc.cache_by_default 1 apc.canonicalize 1 apc.coredump_unmap 0 apc.enable_cli 0 apc.enabled 1 apc.file_md5 0 apc.file_update_protection 2 apc.filters apc.gc_ttl 3600 apc.include_once_override 0 apc.lazy_classes 0 apc.lazy_functions 0 apc.max_file_size 16 apc.mmap_file_mask /tmp/apcphp5.095eRm apc.num_files_hint 1024 apc.preload_path apc.report_autofilter 0 apc.rfc1867 0 apc.rfc1867_freq 0 apc.rfc1867_name APC_UPLOAD_PROGRESS apc.rfc1867_prefix upload_ apc.rfc1867_ttl 3600 apc.serializer default apc.shm_segments 1 apc.shm_size 128M apc.slam_defense 0 apc.stat 0 apc.stat_ctime 0 apc.ttl 7200 apc.use_request_time 1 apc.user_entries_hint 4096 apc.user_ttl 7200 apc.write_lock 1 Host Status Diagrams: Free: 128.0 MBytes (100.0%) Hits: 1 (50.0%) Used: 20.3 KBytes (0.0%) Misses: 1 (50.0%) Detailed Memory Usage and Fragmentation: Fragmentation: 0% phpinfo shows: Server API CGI/FastCGI APC: Version 3.1.9 APC Debugging Enabled MMAP Support Enabled MMAP File Mask /tmp/apcphp5.JkKDk7 Locking type pthread mutex Locks Serialization Support php Revision $Revision: 308812 $ Build Date Jul 21 2011 14:31:12 I followed these steps to find if suexec settings would prevent caching: http://www.litespeedtech.com/support/forum/showthread.php?t=4189 [root@host /]# ps -ef|grep lsphp root 20402 17833 0 11:21 pts/0 00:00:00 grep lsphp [root@host /]# ps -waux root 17833 0.0 0.1 5004 1484 pts/0 S 10:39 0:00 bash ..indicates that there is no lsphp running on the host also I read the following article and comments, concluding that in my case the problem is not the suexec as the user apache is the httpd process owner http://www.brandonturner.net/blog/2009/07/fastcgi_with_php_opcode_cache/ also suexec command is not recognized when logged and launced as root @ host also i'm almost confident that there is no cPanel running on the host to check if a setting there would reset the running cache process at some interval This leaves me with few clues where to head next. I tried to set (with chown and chgrp) apache as the owner of the apc.php file and some test php files resulting in 500 server error. Is there a way to check if the file permissions prevent the apc stay running? I'm tremendously grateful for any suggestions or help.

    Read the article

  • What is causing the unusual high load average?

    - by James
    I noticed on Tuesday night of last week, the load average went up sharply and it seemed abnormal since the traffic is small. Usually, the numbers usually average around .40 or lower and my server stuff (mysql, php and apache) are optimized. I noticed that the IOWait is unusually high even though the processes is barely using any CPU. top - 01:44:39 up 1 day, 21:13, 1 user, load average: 1.41, 1.09, 0.86 Tasks: 60 total, 1 running, 59 sleeping, 0 stopped, 0 zombie Cpu0 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu2 : 0.0%us, 0.3%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu4 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu5 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu6 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu7 : 0.0%us, 0.0%sy, 0.0%ni, 91.5%id, 8.5%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1048576k total, 331944k used, 716632k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 15 0 2468 1376 1140 S 0 0.1 0:00.92 init 1656 root 15 0 13652 5212 664 S 0 0.5 0:00.00 apache2 9323 root 18 0 13652 5212 664 S 0 0.5 0:00.00 apache2 10079 root 18 0 3972 1248 972 S 0 0.1 0:00.00 su 10080 root 15 0 4612 1956 1448 S 0 0.2 0:00.01 bash 11298 root 15 0 13652 5212 664 S 0 0.5 0:00.00 apache2 11778 chikorit 15 0 2344 1092 884 S 0 0.1 0:00.05 top 15384 root 18 0 17544 13m 1568 S 0 1.3 0:02.28 miniserv.pl 15585 root 15 0 8280 2736 2168 S 0 0.3 0:00.02 sshd 15608 chikorit 15 0 8280 1436 860 S 0 0.1 0:00.02 sshd Here is the VMStat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 768644 0 0 0 0 14 23 0 10 1 0 99 0 IOStat - Nothing unusal Total DISK READ: 67.13 K/s | Total DISK WRITE: 0.00 B/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO COMMAND 19496 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19501 be/4 mysql 3.95 K/s 0.00 B/s 0.00 % 0.00 % mysqld 19568 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19569 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19570 be/4 chikorit 11.85 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19571 be/4 chikorit 7.90 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 19573 be/4 chikorit 7.90 K/s 0.00 B/s 0.00 % 0.00 % apache2 -k start 1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % init 11778 be/4 chikorit 0.00 B/s 0.00 B/s 0.00 % 0.00 % top 19470 be/4 mysql 0.00 B/s 0.00 B/s 0.00 % 0.00 % mysqld Load Average Chart - http://i.stack.imgur.com/kYsD0.png I want to be sure if this is not a MySQL problem before making sure. Also, this is a Ubuntu 10.04 LTS Server on OpenVZ. Edit: This will probably give a good picture on the IO Wait top - 22:12:22 up 17:41, 1 user, load average: 1.10, 1.09, 0.93 Tasks: 33 total, 1 running, 32 sleeping, 0 stopped, 0 zombie Cpu(s): 0.6%us, 0.2%sy, 0.0%ni, 89.0%id, 10.1%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1048576k total, 260708k used, 787868k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 15 0 2468 1376 1140 S 0 0.1 0:00.88 init 5849 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 8063 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 9732 root 16 0 8280 2728 2168 S 0 0.3 0:00.02 sshd 9746 chikorit 18 0 8412 1444 864 S 0 0.1 0:01.10 sshd 9747 chikorit 18 0 4576 1960 1488 S 0 0.2 0:00.24 bash 13706 chikorit 15 0 2344 1088 884 R 0 0.1 0:00.03 top 15745 chikorit 15 0 12968 5108 1280 S 0 0.5 0:00.00 apache2 15751 chikorit 15 0 72184 25m 18m S 0 2.5 0:00.37 php5-fpm 15790 chikorit 18 0 12472 4640 1192 S 0 0.4 0:00.00 apache2 15797 chikorit 15 0 72888 23m 16m S 0 2.3 0:00.06 php5-fpm 16038 root 15 0 67772 2848 592 D 0 0.3 0:00.00 php5-fpm 16309 syslog 18 0 24084 1316 992 S 0 0.1 0:00.07 rsyslogd 16316 root 15 0 5472 908 500 S 0 0.1 0:00.00 sshd 16326 root 15 0 2304 908 712 S 0 0.1 0:00.02 cron 17464 root 15 0 10252 7560 856 D 0 0.7 0:01.88 psad 17466 root 18 0 1684 276 208 S 0 0.0 0:00.31 psadwatchd 17559 root 18 0 11444 2020 732 S 0 0.2 0:00.47 sendmail-mta 17688 root 15 0 10252 5388 1136 S 0 0.5 0:03.81 python 17752 teamspea 19 0 44648 7308 4676 S 0 0.7 1:09.70 ts3server_linux 18098 root 15 0 12336 6380 3032 S 0 0.6 0:00.47 apache2 18099 chikorit 18 0 10368 2536 464 S 0 0.2 0:00.00 apache2 18120 ntp 15 0 4336 1316 984 S 0 0.1 0:00.87 ntpd 18379 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 18387 mysql 15 0 62796 36m 5864 S 0 3.6 1:43.26 mysqld 19584 root 15 0 12336 4028 668 S 0 0.4 0:00.02 apache2 22498 root 16 0 12336 4028 668 S 0 0.4 0:00.00 apache2 24260 root 15 0 67772 3612 1356 S 0 0.3 0:00.22 php5-fpm 27712 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 27730 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 30343 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 30366 root 15 0 12336 4028 668 S 0 0.4 0:00.00 apache2 This is the free ram as of today. total used free shared buffers cached Mem: 1024 302 721 0 0 0 -/+ buffers/cache: 302 721 Swap: 0 0 0 Update: Looking into the logs, particularly the PHP5-FPM, which is causing the CPU spike. I found that its segment faulting for some apparent reason. [03-Jun-2012 06:11:20] NOTICE: [pool www] child 14132 started [03-Jun-2012 06:11:25] WARNING: [pool www] child 13664 exited on signal 11 (SIGSEGV) after 53.686322 seconds from start [03-Jun-2012 06:11:25] NOTICE: [pool www] child 14328 started [03-Jun-2012 06:11:25] WARNING: [pool www] child 14132 exited on signal 11 (SIGSEGV) after 4.708681 seconds from start [03-Jun-2012 06:11:25] NOTICE: [pool www] child 14329 started [03-Jun-2012 06:11:58] WARNING: [pool www] child 14328 exited on signal 11 (SIGSEGV) after 32.981228 seconds from start [03-Jun-2012 06:11:58] NOTICE: [pool www] child 15745 started [03-Jun-2012 06:12:25] WARNING: [pool www] child 15745 exited on signal 11 (SIGSEGV) after 27.442864 seconds from start [03-Jun-2012 06:12:25] NOTICE: [pool www] child 17446 started [03-Jun-2012 06:12:25] WARNING: [pool www] child 14329 exited on signal 11 (SIGSEGV) after 60.411278 seconds from start [03-Jun-2012 06:12:25] NOTICE: [pool www] child 17447 started [03-Jun-2012 06:13:02] WARNING: [pool www] child 17446 exited on signal 11 (SIGSEGV) after 36.746793 seconds from start [03-Jun-2012 06:13:02] NOTICE: [pool www] child 18133 started [03-Jun-2012 06:13:48] WARNING: [pool www] child 17447 exited on signal 11 (SIGSEGV) after 82.710107 seconds from start I'm thinking that this might be causing the problem. If that is the cause, probably switching it off that to fastcgi/fcgid might resolve it... but still, I want to see if something else might be causing it to do this.

    Read the article

  • How to use offline mode in Safari

    - by Nathaniel
    So, I'm kind of falling in love with Safari 4 (sorry, Firefox). However, I'm the type who likes my browser cache. Doing a little bit of Googling, it seems Safari does have an offline mode like Firefox, Internet Explorer, and Opera (where you can view cached web pages offline), but I haven't found any way to activate it and just navigating to web pages with no net connection seems not to do it either. So, does Safari even really have an offline mode, and if so, how does one use it?

    Read the article

  • Android emulator performance on linux

    - by Rado
    I installed the android SDK and eclipse plugin on my laptop, but I was surprised to find out that the emulator eats up 100% of one of my cpu cores. I have exactly the same setup on a desktop machine that does not have this issue. Both computers are running arch linux and both were updated yesterday. Granted, the desktop has better hardware than the laptop, but I was expecting to get closer to 50% cpu usage than 100% on the laptop. Both android virtual devices have the same specs: CPU: ARM Target: Android 2.3.3 - API Level 10 Skin: WVGA800 SD Card: 512M hw.lcd.density: 240 vm.heapSize: 24 hw.ramSize: 256 Laptop host has Intel Core 2 T7200 @ 2GHz cpu with 2Gb RAM. Desktop host has AMD Phenom II X4 940 @ 3GHz cpu with 8Gb RAM. The android emulator uses only 1 core and here are the CPU usage results: Laptop: Cpu0 : 22.8%us, 76.5%sy, 0.0%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.3%si, 0.0%st Cpu1 : 11.2%us, 2.4%sy, 0.0%ni, 86.4%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 2055484k total, 1860304k used, 195180k free, 5276k buffers Swap: 2000088k total, 106872k used, 1893216k free, 350780k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2026 xyz 20 0 396m 207m 7192 R 100 10.3 4:11.58 emulator-arm Desktop: Cpu0 : 0.7%us, 0.0%sy, 0.0%ni, 99.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu1 : 1.3%us, 0.0%sy, 0.0%ni, 98.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Cpu2 : 5.0%us, 1.3%sy, 0.0%ni, 91.9%id, 1.7%wa, 0.0%hi, 0.0%si, 0.0%st Cpu3 : 0.3%us, 0.3%sy, 0.0%ni, 99.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 7666324k total, 6506808k used, 1159516k free, 1650960k buffers Swap: 8988348k total, 0k used, 8988348k free, 2867300k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2811 xyz 20 0 392m 220m 6276 S 8 2.9 0:33.58 emulator-arm Is there any way I can improve the emulator performance on the laptop? [UPDATE] I ran the emulator with the same settings, on the same laptop under Win7 and after starting up, it didn't use 100% of a CPU core unlike under linux. Also, I tried running the emulator from a terminal in Linux and I get this message when I don't get it under the desktop Linux host: Could not configure '/dev/hpet' to have a 1024Hz timer. This is not a fatal error, but for better emulation accuracy type: 'echo 1024 /proc/sys/dev/hpet/max-user-freq' as root. I'm not really familiar with rtc or hpet, but it doesn't seem that max-user-freq setting does anything, I still get the same warning.

    Read the article

  • apache mod_cache in v2.2 - enable cache based on url

    - by Janning
    We are using apache2.2 as a front-end server with application servers as reverse proxies behind apache. We are using mod_cache for some images and enabled it like this: <IfModule mod_disk_cache.c> CacheEnable disk / CacheRoot /var/cache/apache2/mod_disk_cache CacheIgnoreCacheControl On CacheMaxFileSize 2500000 CacheIgnoreURLSessionIdentifiers jsessionid CacheIgnoreHeaders Set-Cookie </IfModule> The image urls vary completely and have no common start pattern, but they all end in ".png". Thats why we used the root in CacheEnable / If not served from the cache, the request is forwarded to an application server via reverse proxy. So far so good, cache is working fine. But I really only need to cache all image request ending in ".png". My above configuration still works as my application server send an appropriate Cache-Control: no-cache header on the way back to apache. So most pages send a no-cache header back and they get not cached at all. My ".png" responses doesn't send a Cache-Control header so apache is only going to cache all urls with ".png". Fine. But when a new request enters apache, apache does not know that only .png requests should be considered, so every request is checking a file on disk (recorded with strace -e trace=file -p pid): [pid 19063] open("/var/cache/apache2/mod_disk_cache/zK/q8/Kd/g6OIv@woJRC_ba_A.header", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) I don't want to have apache going to disk every request, as the majority of requests are not cached at all. And we have up to 10.000 request/s at peak time. Sometimes our read IO wait spikes. It is not getting really slow, but we try to tweak it for better performance. In apache 2.4 you can say: <LocationMatch .png$> CacheEnable disk </LocationMatch> This is not possible in 2.2 and as I see no backports for debian I am not going to upgrade. So I tried to tweak apache2.2 to follow my rules: <IfModule mod_disk_cache.c> SetEnvIf Request_URI "\.png$" image RequestHeader unset Cache-Control RequestHeader append Cache-Control no-cache env=!image CacheEnable disk / CacheRoot /var/cache/apache2/mod_disk_cache #CacheIgnoreCacheControl on CacheMaxFileSize 2500000 CacheIgnoreURLSessionIdentifiers jsessionid CacheIgnoreHeaders Set-Cookie </IfModule> The idea is to let apache decide to serve request from cache based on Cache-control header (CacheIgnoreCacheControl default to off). And before simply set a RequestHeader based on the request. If it is not an image request, set a Cache-control header, so it should bypass the cache at all. This does not work, I guess because of late processing of RequestHeader directive, see https://httpd.apache.org/docs/2.2/mod/mod_headers.html#early I can't add early processing as "early" keyword can't be used together with a conditional "env=!image" I can't change the url requesting the images and I know there are of course other solutions. But I am only interested in configuring apache2.2 to reach my goal. Does anybody has an idea how to achieve my goal?

    Read the article

  • Varnish default.vcl grace period

    - by Vladimir
    These are my settings for a grace period (/etc/varnish/default.vcl) sub vcl_recv { .... set req.grace = 360000s; ... } sub vcl_fetch { ... set beresp.grace = 360000s; ... } I tested Varnish using localhost and nodejs as a server. I started localhost, the site was up. Then I disconnected server and the site got disconnected in less than 2 min. It says: Error 503 Service Unavailable Service Unavailable Guru Meditation: XID: 1890127100 Varnish cache server Could you tell me what could be the problem? sub vcl_fetch { if (beresp.ttl < 120s) { ##std.log("Adjusting TTL"); set beresp.ttl = 36000s; ##120s; } # Do not cache the object if the backend application does not want us to. if (beresp.http.Cache-Control ~ "(no-cache|no-store|private|must-revalidate)") { return(hit_for_pass); } # Do not cache the object if the status is not in the 200s if (beresp.status >= 300) { # Remove the Set-Cookie header #remove beresp.http.Set-Cookie; return(hit_for_pass); } # # Everything below here should be cached # # Remove the Set-Cookie header ####remove beresp.http.Set-Cookie; # Set the grace time ## set beresp.grace = 1s; //change this to minutes in case of app shutdown set beresp.grace = 360000s; ## 10 hour - reduce if it has negative impact # Static assets - browser caches tpiphem for a long time. if (req.url ~ "\.(css|js|.js|jpg|jpeg|gif|ico|png)\??\d*$") { /* Remove Expires from backend, it's not long enough */ unset beresp.http.expires; /* Set the clients TTL on this object */ set beresp.http.cache-control = "public, max-age=31536000"; /* marker for vcl_deliver to reset Age: */ set beresp.http.magicmarker = "1"; } else { set beresp.http.Cache-Control = "private, max-age=0, must-revalidate"; set beresp.http.Pragma = "no-cache"; } if (req.url ~ "\.(css|js|min|)\??\d*$") { set beresp.do_gzip = true; unset beresp.http.expires; set beresp.http.cache-control = "public, max-age=31536000"; set beresp.http.expires = beresp.ttl; set beresp.http.age = "0"; } ##do not duplicate these settings if (req.url ~ ".css") { set beresp.do_gzip = true; unset beresp.http.expires; set beresp.http.cache-control = "public, max-age=31536000"; set beresp.http.expires = beresp.ttl; set beresp.http.age = "0"; } if (req.url ~ ".js") { set beresp.do_gzip = true; unset beresp.http.expires; set beresp.http.cache-control = "public, max-age=31536000"; set beresp.http.expires = beresp.ttl; set beresp.http.age = "0"; } if (req.url ~ ".min") { set beresp.do_gzip = true; unset beresp.http.expires; set beresp.http.cache-control = "public, max-age=31536000"; set beresp.http.expires = beresp.ttl; set beresp.http.age = "0"; } ## If the request to the backend returns a code other than 200, restart the loop ## If the number of restarts reaches the value of the parameter max_restarts, ## the request will be error'ed. max_restarts defaults to 4. This prevents ## an eternal loop in the event that, e.g., the object does not exist at all. if (beresp.status != 200 && beresp.status != 403 && beresp.status != 404) { return(restart); } if (beresp.status == 302) { return(deliver); } # Never cache posts if (req.url ~ "\/post\/" || req.url ~ "\/submit\/" || req.url ~ "\/ask\/" || req.url ~ "\/add\/") { return(hit_for_pass); } ##check this setting to ensure that it does not cause issues for browsers with no gzip if (beresp.http.content-type ~ "text") { set beresp.do_gzip = true; } if (beresp.http.Set-Cookie) { return(deliver); } ##if (req.url == "/index.html") { set beresp.do_esi = true; ##} ## check if this is needed or should be used # return(deliver); the object return(deliver); } sub vcl_recv { ##avoid leeching of images call hot_link; set req.grace = 360000s; ##2m ## if one backend is down - use another if (req.restarts == 0) { set req.backend = cache_director; ##we can specify individual VMs } else if (req.restarts == 1) { set req.backend = cache_director; } ## post calls should not be cached - add cookie for these requests if using micro-caching # Pass requests that are not GET or HEAD if (req.request != "GET" && req.request != "HEAD") { return(pass); ## return(pass) goes to backend - not cache } # Don't cache the result of a redirect if (req.http.Referer ~ "redir" || req.http.Origin ~ "jumpto") { return(pass); } # Don't cache the result of a redirect (asking for logon) if (req.http.Referer ~ "post" || req.http.Referer ~ "submit" || req.http.Referer ~ "add" || req.http.Referer ~ "ask") { return(pass); } # Never cache posts - ensure that we do not use these strings in our URLs' that need to be cached if (req.url ~ "\/post\/" || req.url ~ "\/submit\/" || req.url ~ "\/ask\/" || req.url ~ "\/add\/") { return(pass); } ## if (req.http.Authorization || req.http.Cookie) { if (req.http.Authorization) { /* Not cacheable by default */ return (pass); } # Handle compression correctly. Different browsers send different # "Accept-Encoding" headers, even though they mostly all support the same # compression mechanisms. By consolidating these compression headers into # a consistent format, we can reduce the size of the cache and get more hits. # @see: http:// varnish.projects.linpro.no/wiki/FAQ/Compression if (req.http.Accept-Encoding) { if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|ico)$") { # No point in compressing these remove req.http.Accept-Encoding; } else if (req.http.Accept-Encoding ~ "gzip") { # If the browser supports it, we'll use gzip. set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate") { # Next, try deflate if it is supported. set req.http.Accept-Encoding = "deflate"; } else { # Unknown algorithm. Remove it and send unencoded. unset req.http.Accept-Encoding; } } # lookup graphics, css, js & ico files in the cache if (req.url ~ "\.(png|gif|jpg|jpeg|css|.js|ico)$") { return(lookup); } ##added on 0918 - check if it causes issues with user specific content if (req.request == "GET" && req.http.cookie) { return(lookup); } # Pipe requests that are non-RFC2616 or CONNECT which is weird. if (req.request != "GET" && req.request != "HEAD" && req.request != "PUT" && req.request != "POST" && req.request != "TRACE" && req.request != "OPTIONS" && req.request != "DELETE") { ##closing connection and calling pipe return(pipe); } ##purge content via localhost only if (req.request == "PURGE") { if (!client.ip ~ purge) { error 405 "Not allowed."; } return(lookup); } ## do we need this? ## return(lookup); }

    Read the article

  • Firefox - setting/extension to toggle between showing & hiding of all images, without reloading the page

    - by galacticninja
    I'm looking for a Firefox setting or extension that can easily toggle between showing and hiding of all images without reloading the page (similar to Opera's feature - the 'Show only cached images' feature is preferable, but optional in my case). I have found an extension that can show/hide images (Image-Show-Hide) but it needs to reload the page to show/hide the images. I prefer that the page not reload when unhiding images from a page previously set to hide all images.

    Read the article

  • IIS seems to be caching files on a system share?

    - by scott novell
    Switching over to windows 2008 and IIS 7.5 and it seems whenever I make a change to a css file on a system share it does not show through the browser for a few mins. It is shown through the browser using an ISAPI filter. I have turned off output caching in IIS and also turned off caching on the share itself. The browser is not caching either forcing a 200 and it is cached. Any ideas

    Read the article

  • How mod_cache working with "must-revalidate" and "max-age"?

    - by Dmitriy Sosunov
    Quick question before I will explain my flow: ?an mod_cache perform revalidate with if-none-match only if max-age is expired in case if it configured in reverse proxy mode? My goal is to reduce a number of revalidation requests to our the origin server. For instance: The first request goes to the origin server and then mod_cache save a response in to the cache according to header cache-control: max-age. And only when max-age is expired then mod_cache will revalidate with if-none-match. Currently, mod_cache revalidate each request, regardless that max-age is defined or not. My configuration of Apache 2.4.3 (Windows), on linux I see the same behavior that I will show below. ServerName proxy.lo ProxyRequests Off ProxyPreserveHost Off Header set Vary "Accept, Content-Type, Content-Encoding, Accept-Language" RequestHeader set X-Forwarded-Proto "http" # modify header for user agent's Header set Cache-Control "private, no-cache, no-store, no-transform" CacheQuickHandler off CacheDefaultExpire 300 # the origin server do not provide last-modified CacheIgnoreNoLastMod On CacheIgnoreCacheControl On # the origin server define cache-control: private, no-store only for user agents # Therefore, I would like ignore those headers on the proxy server. CacheStorePrivate On CacheStoreNoStore On CacheEnable disk / CacheRoot "C:/Apache.Cache" CacheDirLevels 5 CacheDirLength 4 CacheMinExpire 15 CacheDetailHeader on CacheHeader on KeepAlive Off ProxyPass / http://origin.lo/ ProxyPassReverse / http://origin.lo/ Also, I have turned on debug log level to see how mod_cache handles a content for caching: I provided this to show that mod_proxy always decides that a content isn't fresh. Why?I provided this to show that mod_proxy always decide that a content isn't fresh. Why? max-age was provided (see below). [Sun Nov 04 11:58:42.899890 2012] [cache:debug] [pid 6492:tid 1400] cache_storage.c(624): [client 192.168.1.100:63741] AH00698: cache: Key for entity /testpage?(null) is http://proxy.lo/testpage? [Sun Nov 04 11:58:42.899890 2012] [cache_disk:debug] [pid 6492:tid 1400] mod_cache_disk.c(569): [client 192.168.1.100:63741] AH00709: Recalled cached URL info header http://proxy.lo/testpage? [Sun Nov 04 11:58:42.899890 2012] [cache_disk:debug] [pid 6492:tid 1400] mod_cache_disk.c(865): [client 192.168.1.100:63741] AH00720: Recalled headers for URL http://proxy.lo/testpage? [Sun Nov 04 11:58:42.899890 2012] [cache:debug] [pid 6492:tid 1400] cache_storage.c(320): [client 192.168.1.100:63741] AH00695: Cached response for /testpage isn't fresh. Adding/replacing conditional request headers. [Sun Nov 04 11:58:42.899890 2012] [cache:debug] [pid 6492:tid 1400] mod_cache.c(414): [client 192.168.1.100:63741] AH00757: Adding CACHE_SAVE filter for /testpage [Sun Nov 04 11:58:42.899890 2012] [cache:debug] [pid 6492:tid 1400] mod_cache.c(448): [client 192.168.1.100:63741] AH00759: Adding CACHE_REMOVE_URL filter for /testpage [Sun Nov 04 11:58:42.899890 2012] [proxy:debug] [pid 6492:tid 1400] mod_proxy.c(1068): [client 192.168.1.100:63741] AH01143: Running scheme http handler (attempt 0) [Sun Nov 04 11:58:42.899890 2012] [proxy:debug] [pid 6492:tid 1400] proxy_util.c(1976): AH00942: HTTP: has acquired connection for (origin.lo) [Sun Nov 04 11:58:42.899890 2012] [proxy:debug] [pid 6492:tid 1400] proxy_util.c(2029): [client 192.168.1.100:63741] AH00944: connecting http://origin.lo/testpage to origin.lo:80 [Sun Nov 04 11:58:42.901890 2012] [proxy:debug] [pid 6492:tid 1400] proxy_util.c(2151): [client 192.168.1.100:63741] AH00947: connected /testpage to origin.lo:80 [Sun Nov 04 11:58:42.901890 2012] [proxy:debug] [pid 6492:tid 1400] proxy_util.c(2554): AH00962: HTTP: connection complete to 192.168.1.100:80 (origin.lo) [Sun Nov 04 11:58:42.903890 2012] [proxy:debug] [pid 6492:tid 1400] proxy_util.c(1991): AH00943: http: has released connection for (origin.lo) [Sun Nov 04 11:58:42.903890 2012] [headers:debug] [pid 6492:tid 1400] mod_headers.c(800): AH01502: headers: ap_headers_output_filter() [Sun Nov 04 11:58:42.903890 2012] [cache:debug] [pid 6492:tid 1400] mod_cache.c(1190): [client 192.168.1.100:63741] AH00769: cache: Caching url: /testpage [Sun Nov 04 11:58:42.903890 2012] [cache:debug] [pid 6492:tid 1400] mod_cache.c(1196): [client 192.168.1.100:63741] AH00770: cache: Removing CACHE_REMOVE_URL filter. [Sun Nov 04 11:58:42.904890 2012] [cache_disk:debug] [pid 6492:tid 1400] mod_cache_disk.c(1318): [client 192.168.1.100:63741] AH00737: commit_entity: Headers and body for URL http://proxy.lo/testpage? cached. The first request to the origin server without mod_proxy to http://origin.lo/ GET http://origin.lo/testpage HTTP/1.1 Host: origin.lo Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: application/json Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 The first response from the origin without mod_proxy HTTP/1.1 200 OK Cache-Control: must-revalidate, proxy-revalidate, max-age=30 Content-Type: application/json; charset=utf-8 ETag: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Server: Microsoft-IIS/7.5 X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET Date: Sun, 04 Nov 2012 10:11:01 GMT Content-Length: 1877 So, I assumed that revalidation must be occur only in 30 seconds after the success response. Is't right? Let's check it:) Within 30 sec, the Google Chrome didn't perform any requests to the origin server to revalidate a request and has return the response from local cache. When max-age is expired, the Google Chrome perform a request to revalidate: GET http://origin.lo/testpage HTTP/1.1 Host: origin.lo Connection: keep-alive Cache-Control: max-age=0 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: application/xml If-None-Match: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 and response: HTTP/1.1 304 Not Modified Cache-Control: must-revalidate, proxy-revalidate, max-age=30 ETag: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Server: Microsoft-IIS/7.5 X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET Date: Sun, 04 Nov 2012 10:16:20 GMT As you can see, all works as expected. User agent revalidates request only when max-age is expired. Let's now try perform the folling flow though mod_proxy (see configuration above). The first request: GET http://proxy.lo/testpage HTTP/1.1 Host: proxy.lo Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: application/json Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 and the response was: HTTP/1.1 200 OK Date: Sun, 04 Nov 2012 10:23:36 GMT Server: Apache Cache-Control: private, no-cache, no-store, no-transform Content-Type: application/json; charset=utf-8 ETag: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Content-Length: 1932 Vary: Accept,Content-Type,Content-Encoding,Accept-Language X-Cache: MISS from proxy.lo X-Cache-Detail: "cache miss: attempting entity save" from proxy.lo Connection: close Ok, let's see to the disk cache and try to see how request and response was stored. (I cut binary data) http://proxy.lo/testpage? Cache-Control: private, no-cache, no-store, no-transform Content-Type: application/json; charset=utf-8 ETag: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Date: Sun, 04 Nov 2012 10:27:15 GMT Content-Length: 1932 Vary: Accept, Content-Type, Content-Encoding, Accept-Language Host: proxy.lo User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: application/json Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 X-Forwarded-Proto: http Cache-Control: max-age=300, must-revalidate X-Forwarded-For: 192.168.1.100 X-Forwarded-Host: proxy.lo X-Forwarded-Server: origin.lo Ok, what we see? We see that the first request was performed with max-age=300 & must-revalidate Ok, looks good, as for me, lets perform the next call: GET http://proxy.lo/testpage HTTP/1.1 Host: proxy.lo Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: application/json Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 and the second response from mod_proxy: HTTP/1.1 200 OK Date: Sun, 04 Nov 2012 10:31:58 GMT Server: Apache Cache-Control: private, no-cache, no-store, no-transform ETag: "7cf651e2-176f-4ac1-808e-0e0c17cfd0a2" Content-Length: 1932 Vary: Accept,Content-Type,Content-Encoding,Accept-Language X-Cache: REVALIDATE from proxy.lo X-Cache-Detail: "conditional cache hit: entity refreshed" from proxy.lo Connection: close Content-Type: application/json; charset=utf-8 SO, MY QUESTION IS: WHY mod_proxy perform revalidation on each request regardless that max-age is defined? N.B. Apache 2.4.3 Thanks, I would be grateful for any help.

    Read the article

  • Apache and MySQL taking all the memory? Maximum connections?

    - by lpfavreau
    I've a had one of our servers going down (network wise) but keeping its uptime (so looks the server is not losing its power) recently. I've asked my hosting company to investigate and I've been told, after investigation, that Apache and MySQL were at all time using 80% of the memory and peaking at 95% and that I might be needing to add some more RAM to the server. One of their justifications to adding more RAM was that I was using the default max connections setting (125 for MySQL and 150 for Apache) and that for handling those 150 simultaneous connections, I would need at least 3Gb of memory instead of the 1Gb I have at the moment. Now, I understand that tweaking the max connections might be better than me leaving the default setting although I didn't feel it was a concern at the moment, having had servers with the same configuration handle more traffic than the current 1 or 2 visitors before the lunch, telling myself I'd tweak it depending on the visits pattern later. I've also always known Apache was more memory hungry under default settings than its competitor such as nginx and lighttpd. Nonetheless, looking at the stats of my machine, I'm trying to see how my hosting company got those numbers. I'm getting: # free -m total used free shared buffers cached Mem: 1000 944 56 0 148 725 -/+ buffers/cache: 71 929 Swap: 1953 0 1953 Which I guess means that yes, the server is reserving around 95% of its memory at the moment but I also thought it meant that only 71 out of the 1000 total were really used by the applications at the moment looking a the buffers/cache row. Also I don't see any swapping: # vmstat 60 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 57612 151704 742596 0 0 1 1 3 11 0 0 100 0 0 0 0 57604 151704 742596 0 0 0 1 1 24 0 0 100 0 0 0 0 57604 151704 742596 0 0 0 2 1 18 0 0 100 0 0 0 0 57604 151704 742596 0 0 0 0 1 13 0 0 100 0 And finally, while requesting a page: top - 08:33:19 up 3 days, 13:11, 2 users, load average: 0.06, 0.02, 0.00 Tasks: 81 total, 1 running, 80 sleeping, 0 stopped, 0 zombie Cpu(s): 1.3%us, 0.3%sy, 0.0%ni, 98.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1024616k total, 976744k used, 47872k free, 151716k buffers Swap: 2000052k total, 0k used, 2000052k free, 742596k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 24914 www-data 20 0 26296 8640 3724 S 2 0.8 0:00.06 apache2 23785 mysql 20 0 125m 18m 5268 S 1 1.9 0:04.54 mysqld 24491 www-data 20 0 25828 7488 3180 S 1 0.7 0:00.02 apache2 1 root 20 0 2844 1688 544 S 0 0.2 0:01.30 init ... So, I'd like to know, experts of serverfault: Do I really need more RAM at the moment? How do they calculate that for 150 simultaneous connections I'd need 3Gb? Thanks for your help!

    Read the article

  • Blank graph for some munin plugins

    - by jack
    I have a munin-master and munin-node installed on same server (Ubuntu 9.10 server). Most pre-installed plugins work well but the following plugins are with blank graph: Memcached bytes used Memcached connections Memcached cache hits and misses Memcached cached items Memcached requests Memcached network traffic MySQL Queries Cache Size I run the following 3 script in terminal and results were ok. /etc/munin/plugins/memcached_bytes /etc/munin/plugins/memcached_counters /etc/munin/plugins/memcached_rates But when I tried the command below after "telnet localhost 4949" fetch memcached_bytes # Unknown service etch memcached_bytes_ # timeout pid 28009 - killing...done Does anyone know the reason?

    Read the article

  • Memory Usage for Databases on Linux

    - by Kyle Brandt
    So with free output what we care about with application memory usage is generally the amount of free memory in the -/+ buffers/cache line. What about with database applications such as Oracle, is it important to have a good amount of cached and buffers available for a database to run well with all the IO? If that makes any sense, how do you figure out just how much?

    Read the article

  • Remove deleted posts from central google reader cache

    - by bogdanbrudiu
    After posting some test blog entries, I then remove them from my blog. however, once loaded by google reader, they never disappear from it. Even if I sign up to my blog feed from a different account, they still appear, so it seems that they are centrally cached by google reader. How can I force google reader to delete them from cache?

    Read the article

  • centos 6 ps aux hangs up

    - by Guntis
    I have problem with my server. Server is running centos 6 (CloudLinux Server release 6.2). uname -a = 2.6.32-320.4.1.lve1.1.4.el6.x86_64 That is a kvm guest. On host is debian 6. If i run command ps aux, it stuck on random process (shows some processes only), top command is working fine. htop doesn't work too (black screen). top - 12:11:51 up 34 min, 1 user, load average: 4.26, 6.71, 16.15 Tasks: 201 total, 7 running, 192 sleeping, 0 stopped, 2 zombie Cpu(s): 7.9%us, 2.8%sy, 0.0%ni, 87.5%id, 1.6%wa, 0.0%hi, 0.2%si, 0.0%st Mem: 9862044k total, 2359484k used, 7502560k free, 171720k buffers Swap: 10485720k total, 0k used, 10485720k free, 1336872k cached server has one Intel(R) Xeon(R) CPU E5606 @ 2.13GHz, free -m total used free shared buffers cached Mem: 9630 2336 7293 0 170 1324 -/+ buffers/cache: 841 8789 Swap: 10239 0 10239 php -v PHP 5.3.19 (cli) (built: Nov 28 2012 10:03:07) Copyright (c) 1997-2012 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies with the ionCube PHP Loader v4.2.2, Copyright (c) 2002-2012, by ionCube Ltd., and with Zend Guard Loader v3.3, Copyright (c) 1998-2010, by Zend Technologies with Suhosin v0.9.33, Copyright (c) 2007-2012, by SektionEins GmbH mysql Server version: 5.1.63-cll php -i disable_functions => apache_child_terminate, apache_setenv, define_syslog_variables, escapeshellarg, escapeshellcmd, eval, exec, fp, fput, ftp_connect, ftp_e xec, ftp_get, ftp_login, ftp_nb_fput, ftp_put, ftp_raw, ftp_rawlist, highlight_file, ini_alter, ini_get_all, ini_restore, inject_code, openlog, passthru, php _uname, phpAds_remoteInfo, phpAds_XmlRpc, phpAds_xmlrpcDecode, phpAds_xmlrpcEncode, popen, posix_getpwuid, posix_kill, posix_mkfifo, posix_setpgid, posix_set sid, posix_setuid, posix_setuid, posix_uname, proc_close, proc_get_status, proc_nice, proc_open, proc_terminate, shell_exec, syslog, system, xmlrpc_entity_de code, xmlrpc_server_create, putenv, show_source,mail => apache_child_terminate, apache_setenv, define_syslog_variables, escapeshellarg, escapeshellcmd, eval, exec, fp, fput, ftp_connect, ftp_exec, ftp_get, ftp_login, ftp_nb_fput, ftp_put, ftp_raw, ftp_rawlist, highlight_file, ini_alter, ini_get_all, ini_restore, inject_code, openlog, passthru, php_uname, phpAds_remoteInfo, phpAds_XmlRpc, phpAds_xmlrpcDecode, phpAds_xmlrpcEncode, popen, posix_getpwuid, posix_kill, pos ix_mkfifo, posix_setpgid, posix_setsid, posix_setuid, posix_setuid, posix_uname, proc_close, proc_get_status, proc_nice, proc_open, proc_terminate, shell_exe c, syslog, system, xmlrpc_entity_decode, xmlrpc_server_create, putenv, show_source,mail ... suhosin.executor.disable_eval => Off => Off suhosin.executor.eval.blacklist => include,include_once,require,require_once,curl_init,fpassthru,base64_encode,base64_decode,mail,exec,system,proc_open,leak, syslog,pfsockopen,shell_exec,ini_restore,symlink,stream_socket_server,proc_nice,popen,proc_get_status,dl, pcntl_exec, pcntl_fork, pcntl_signal,pcntl_waitpid, pcntl_wexitstatus, pcntl_wifexited, pcntl_wifsignaled,pcntl_wifstopped, pcntl_wstopsig, pcntl_wtermsig, socket_accept,socket_bind, socket_connect, socket_cr eate, socket_create_listen,socket_create_pair,link,register_shutdown_function,register_tick_function,gzinflate => include,include_once,require,require_once,c url_init,fpassthru,base64_encode,base64_decode,mail,exec,system,proc_open,leak,syslog,pfsockopen,shell_exec,ini_restore,symlink,stream_socket_server,proc_nic e,popen,proc_get_status,dl, pcntl_exec, pcntl_fork, pcntl_signal,pcntl_waitpid, pcntl_wexitstatus, pcntl_wifexited, pcntl_wifsignaled,pcntl_wifstopped, pcntl _wstopsig, pcntl_wtermsig, socket_accept,socket_bind, socket_connect, socket_create, socket_create_listen,socket_create_pair,link,register_shutdown_function, register_tick_function,gzinflate Sometimes i cannot kill httpd process. I run kill -9 PID even several times, and nothing happens. php runs via suphp. I learned somewhere that it can be trojan. I ran strace ps aux and it stops on open("/proc/PID/cmdline", O_RDONLY) If i reboot server, problem is gone but after some time it is back again .. :( Thanks.

    Read the article

  • How to enable caching on Apache2 (using as load balancer)

    - by csl
    I'm using Apache 2 as my load balancer (mod_jk). I've 2 Tomcat servers behind my load balancer. What I'm trying to do is to enable caching of my static pages in my load balancer using mod_cache but nothing seems to be working. I confirmed this by creating a simple JSP page that prints out current date time and I always get the latest date time (indicating that the JSP page is not cached). OS: Ubuntu

    Read the article

< Previous Page | 16 17 18 19 20 21 22 23 24 25 26 27  | Next Page >