latency optimizer

Label: style blog HTTP use ar sp 2014 art C Although the phase frequency response should reflect the processing time of different frequency signals, it does not mean that the larger the phase frequency response, the longer the system processing time. We can know from a simple sine signal exp (J * w * n) that the phase is w * n, that is, the phase is not only related to time, but also frequency. In signal processing, group delay is another concept used to characterize the system delay time. Its

MySQL master-slave replication is an important part of the MySQL high-availability architecture. It can be used to achieve load balancing, high availability and failover, and provide backup. For master-slave replication monitoring, it is not reliable to rely solely on the showslavestatus provided by MySQL itself. Pt-heartbeat is a good choice for master-slave replication latency monitoring. This article describes MySQL master-slave replication is an i

timing precision requirements, such as dynamic display of Bitmap. Method 2: Use the sleep () function in VC to implement latency. Its unit is ms. For example, if the latency is 2 seconds, use sleep (2000 ). The accuracy is very low, and the minimum timing accuracy is only 30 ms. The disadvantage of using the sleep function is that other messages cannot be processed during the delay period. If the time is t

In Android, latency functions are divided into user space and kernel space: Kernel space # Include Udelay (int n ); Mdelay (INT n )); Ndelay (INT n )); These functions will lead to an endless cycle of CPU and lead to a busy wait of CPU. Usleep (int n ); Msleep (INT n )); Nsleep (INT n )); The difference between the first group and the second group of latency functions is that the first group of

We know that there are many concepts in computers that are not easy to understand. sometimes, a good analogy can beat many explanations. The following are two wonderful metaphors I have seen. let's share them with you. The first analogy is about throughput and latency. We know that there are many concepts in computers that are not easy to understand. sometimes, a good analogy can beat many explanations. The following are two wonderful metaphors I have

When you submit a query, MySQL will analyze it to see if some optimization can be done to make it faster to process the query. This section describes how the query optimizer works. If you want to know the optimization methods used by MySQL, you can refer to the MySQL reference manual. Of course, the MySQL query optimizer also uses indexes, but it also uses other information. For example, if you submit a que

Query Optimizer Kernel Analysis article 1 Query Optimizer Kernel Analysis article 1 Query Optimizer Kernel Analysis article 2: Generate candidate execution plans Execution plan cost estimation Query Optimizer Kernel Analysis article 3: query execution and plan Cache Hint prompt Query

This article uses a case to see how the MySQL optimizer selects the index and JOIN sequence. For Table Structure and data preparation, refer to the test environment at the end of this article. Here we will mainly introduce the main execution process of the MySQL optimizer, rather than the various components of an optimizer (this is another topic ). We know that t

Label:If you are dissatisfied with the execution plan selected by the optimizer, you can use several hints provided by the optimizer to control the final execution plan, the specific usage of each hint, the recommended direct reading of the official manual, some hints and versions have a direct relationship, some of the tips you can use are as follows: High_priority and low_priority: This tip tells MySQL wh

MySQL master-slave database synchronization latency problem solved recently I was conducting a MySQL master-slave database synchronization test and found some problems, among which the master-slave synchronization latency problem is one of them. the following content is some explanations found on the Internet, record it for your own learning; The master-slave synchronization of MySQL is a mature architectu

Hello everyone, welcome back to the 22nd week of Performance tuning training . Last week I talked about the baseline in SQL Server, and today we go ahead and talk about waiting and I/O latency statistics in SQL Server. When I perform a SQL Server health check, I always use these 2 dimensions to globally master the health of SQL Server.Wait statistics (wait Statistics)Every time you execute a query in SQL Server, the query waits. This looks bleak for t

(current-> timeout> 0 ){Early = Current-> timeout-jiffies;Current-> timeout = 0;}Return early;}3. If you do not need to wait for other events, you can directly wait for a delay.Extern inline voidSchedule_timeout(INT timeout){Current-> timeout = jiffies + timeout;Current-> state = task_interruptible;Schedule ();Current-> timeout = 0;}Set_current_state (task_interruptible );Schedule_timeout (jit_delay * Hz );4We recommend a maximum of 1000us for short latency