webroot performance issues

analysis. The following script will help us list a session that has opened a transaction but is not active, that is, open a transaction, but no statements have been executed for the last 30 seconds. 1 /***************************************************************************************** 2 STEP 4:list The Open session with transaction which are not active3 ****************************************************************************************/ 4 SELECT es.session_id,5 Es.login_name,6 es. HO

on this mechanism, the problem cannot be solved completely.So does this mean that PHP can only be used for small sites and not be able to perform on large, high-volume sites? Of course not. In fact, PHP is used extensively on Yahoo and many other well-known giant websites. The reason is that PHP is only used as a content generator, the generated content will be converted to static text, the vast majority of users are browsing the cache of static text. This has nothing to do with the

Ever since I used EF, I've been concerned about potential performance issues every time. So every time I write a LINQ query, I use SQL Profiler to look at the actual generated SQL statements to uncover potential performance problems. It is also strongly recommended that you do so to avoid the future of the software is a problem difficult to check.One, select only

Tools Description jps JVM Process Status Tool jstat JVM Statistics Monitoring Tool jstatd JVM Jstat Daemon jpsTool lists the virtual machines for the current user of the target system. This is particularly useful for environments that use the JNI invocation API instead of the standard Java launcher to launch VMS. In these environments, it is often difficult to identify Java processes from the lis

index, and if the condition is like '%abc ', MySQL will not use the index.ü In an order by operation, MySQL uses the index only if the sort condition is not a query condition expression. However, in queries involving multiple data tables, even if an index is available, those indexes have little effect in accelerating the order by operation.ü If a data column contains many duplicate values, it will not be very effective even if you set up an index for it. For example, if a data column contains t

node.task_address=er.task_addressPanax Notoginseng Left JOIN - (SELECT session_id, SUM (Wait_duration_ms) as theWait_duration_ms,wait_type,blocking_session_id,count (*) as Nothread + From SYS. Dm_os_waiting_tasks GROUP by session_id, wait_type,blocking_session_id) WT AOn wt.session_id=er.session_id the Cross apply SYS. Dm_exec_sql_text (Er.sql_handle) as Sqltxt +WHERE sql_handle is not NULL and ISNULL (Wt.wait_type,"') not in -('WAITFOR','broker_receive_waitfor') $ ORDER by Er.total_elapsed_ti

Original: Initial SQL Server performance issue (4/4): List the most resource-consuming sessionsIn the last 3 articles, we discussed a list of different queries that reflect the current state of the server. Initial SQL Server performance issues (1/4): Server overview Initial SQL Server performance

IE is not as stupid as we think. It knows that the total number of cycles is still 10 million. Therefore, we need to separate these one hundred cycles. Although Javascript is single-threaded, you can use setTimeout or setInterval to simulate multithreading. Suppose we want to generate 10 million random numbers. The general practice is as follows: var numbers = []; for (var i = 0; i However, when executing this code in IE, a window is displayed prompting you whether to stop the script. In this

Overreleased object that detects the complete memory of the zombie. Note that this memory history is the only part of the allocation instrument in the use of meaningful zombie tracking templates. discover Zombies in your code Open the zombie template. Select your app to select a target from the pop-up menu. Click the Record button and run your app. When a zombie gives a dialog box, click the Message Text dialog box to the right of the attention button. Open the Extended

1.cell has too many sub-views, which adds to the burden of the cell2. When loading the picture, choose asynchronous load, loads the cable in the sub-line3. Avoid cell re-layout. cell layout fills are time-consuming and generally well laid out when created. 4. Do not use Clearcolor, no background color, and do not set the opacity to 05.layoutSubviews This method will be called in the cell, scrolling table, and so on, and the call is very frequent, so this method try not to write time-consuming op

=NewBackgroundtasks01{Console.WriteLine ("Blogname:{0},blogid:{1}", blog. Blogname, blog. BLOGID);});inti =0; while(I++ -) {bg. ADD (NewBlog () {BlogId = i, Blogname ="Default" });} Console.ReadLine (); BG. ADD (NewBlog () {BlogId = +, Blogname ="Zhang San"}); bg. ADD (NewBlog () {BlogId =1001, Blogname ="John Doe"});View CodeThis design solves both asynchronous execution and resource-occupying problems.But there is no perfect thing in the world, the code is the same, because the task in the q

interfaceRegisterfun_getinstance (EXT)Return Ext,ext.supperEnd---Inheriting object instances[Email protected] #table Ext instance of current object[email protected] An instance #table base base classfunction Inheritance (ext,base)--Assert (False, "call this function can only be accessed through supper, if how much inheritance, only the last inheritance will take effect")return Inheritancea (ext or {},base, "__supper")End---inherit from model file[Email protected] #table Ext instance of current

Deadlock Example program: ThreadTest, which is a classic example of a deadlock that occurs with synchronous nesting; Public classThreadTest { Public StaticObject Lock1 =NewObject (); Public StaticObject Lock2 =NewObject (); Public Static voidmethod1 () {Trace ("Inside method1"); synchronized(lock1) {Trace ("Method1 got Lock1"); DoSomething (); synchronized(Lock2) {Trace ("Method1 got Lock2, sleeping"); DoSomething (); Trace ("Method1 Returning"); } } } P

Scene:Simulate a day's data, each 10 seconds, traverse 1000 devices, each device simulates a real-time data, the total amount of data is: 24*60*60/10*1000 = 8.64 million records.--------------------------------------------------------------------------------------------------------------- ------Strategy: For time-phased, splicing SQL statement query.1, to a device, the average day per hour, the time spent 3 minutes.2, the Domainid+devicecode+eventtime index, the time cost 10 seconds.------------

In the last 3 articles, we discussed a list of different queries that reflect the current state of the server. Initial SQL Server performance issues (1/4): Server overview Initial SQL Server performance issues (2/4): List the sessions waiting for resources Initial SQL Server

corresponding domain name queue, send and update the last send time of the changed domain name.2. Unlock the domain to send records.In this way, the non-blocking queue is used for message queue, which improves the concurrency of the system.It seems to solve the problem, but it was blacklisted by some service providers.The system is then analyzed as follows:This is a typical producer-to-consumer issue in which Java client-produced messages are timed to be pushed to the postfix queue, and then po

); } else {synchronized (monitor ()) {newObj = Setterhelper (obj); }}} and else if (nosyncthis) {if (nosyncobj) {newObj = Setterhelper (obj); } else {synchronized (Obj.monitor ()) {newObj = Setterhelper (obj); }}}} else {if (nosyncobj) {synchronized (monitor ()) { NEWOBJ = Setterhelper (obj); }} Boolean acquired = FALSE; try {globallock.acquire (); acquired = true; Synchronized (monitor ()) {synchronized (Obj.monitor ()) {globallock.rel

normal, we can rule out the problem with the database server, the slow response may be caused by blocking that we cannot control, or only some of the sessions are slow, not the entire server.This is the 1th step of the problem analysis of diagnostic methods, the next article will explain how to deal with the following.2 drawings to help you understand the relationship between tasks, workers (works), scheduling (schedulers).For each cpu,sqlserver there will be a scheduler corresponding to it. In

0.00 0.10 0.00 0.00 0.00 0.0011:55 36 sec IFACE rxpck/s txpck/s rxkb/s txkb/s rxcmp/s txcmp/s rxmcst/s11:55 38 sec Lo 0.00 0.00 0.00 0.00 0.00 0.00 0.0011:55 38 sec eth0 14.50 0.00 0.88 0.00 0.00 0.00 0.00Average time: IFACE rxpck/s txpck/s rxkb/s txkb/s rxcmp/s txcmp/s rxmcst/sAverage time: Lo 0.67 0.67 0.04 0.04 0.00 0.00 0.00Average time: eth0 6.17 0.17 0.43 0.01 0.00 0.00 0.00IFACE: Network Interface DeviceRXPCK/S: Packet size received per secondTXPCK/S: Packet size sent per secondrxkb/s: N

PHP write a very simple interface, with a JSON file to do a simple database, with the increase in data, will there be performance problems? Do you have performance issues with multiple meetings? The size of the JSON file is expected to grow slowly and should not exceed 5M in 1 years Reply content: PHP write a very simple interface, with a JSON file to do a s