Error analysis and positioning A database cluster is used in the project. When using it, it is found that the project is running and the database has not been operated for a period of time. If the database is operated again after a period of time, the following error will appear on the console. Failed […]
Tag: pool
Handwritten ThreadPoolExecutor thread pool
Many people don’t recommend making wheels, but I don’t. I built the wheel not to use it in a production environment, but to deepen my understanding. Why not? I personally think that making wheels is almost the best way to learn, if not even one. Because making a wheel requires doing at least the following […]
Analysis and application of connection pool in Python
Connection Pool (Connection Pool) stores network connections as objects in memory during system initialization. When the user needs to connect, an established empty connection object is taken from the connection pool and the connection is not closed after use. , put the connection back into the connection pool without having to frequently create and close […]
How to Properly Estimate Java Thread Pool Size: A Comprehensive Guide
Thread creation in Java incurs significant costs. Creating threads consumes time, increases request processing latency, and involves a lot of work for both the JVM and the operating system. To alleviate these overheads, thread pools come into play. In this article, we’ll delve into the art of determining the ideal thread pool size. A fine-tuned […]
The four kings + part of the thread pool knowledge under the JUC package
1) Semphore: I am right to use the current limiter The semaphore in Java encapsulates the native semaphore of the operating system. It is essentially a counter that describes the number of available resources and mainly involves two operations. If the counter is 0 and the operation continues, blocking and waiting will occur. P operation: […]
C++ uses thread pool to simulate asynchronous event processing mechanism
There are asynchronous event processing mechanisms in many C++ frameworks, which makes us often confused and difficult to understand when looking at the source code. The programming routines contained in it may be some mature technologies that we are not familiar with, such as WebRTC. It is similar to Qt’s signal and slot mechanism, thread […]
Java thread pool – Executor framework
Article directory 1. Executor interface 2. ExecutorService interface 3. ThreadPoolExecutor class 1. Status 2. Worker 3. Extension 4. ForkJoinPool class 1. Work stealing algorithm 2. Fork/Join design 3. Execution principle 5. ScheduledThreadPool class 1.ScheduledExecutorService 2. Compare Timer 6. Executors class The Executor framework was introduced after Java 5. After Java 5, starting threads through Executor […]
Spring’s own thread pool ThreadPoolTaskExecutor
Spring default thread pool simpleAsyncTaskExecutor The interface class of Spring asynchronous thread pool is TaskExecutor, which is essentially java.util.concurrent.Executor. If there is no configuration, simpleAsyncTaskExecutor is used by default. @Async demonstrates Spring’s default simpleAsyncTaskExecutor @Component @EnableAsync public class ScheduleTask {<!– –> SimpleDateFormat sdf = new SimpleDateFormat(“yyyy-MM-dd HH:mm:ss”); @Async @Scheduled(fixedRate = 2000) public void testScheduleTask() {<!– […]
pgpool-II + keepalived achieves high availability
Installation Download https://pgpool.net/mediawiki/index.php/Downloads Compile and install tar -zxvf pgpool-II-4.4.4.tar.gz cd pgpool-II-4.4.4.tar.gz ./configure –prefix=/usr/local/pgpool –with-pgsql=/usr/local/postgres/ make & amp; & amp; make install #pgpool-regclass plug-in installation cd /root/pgpool-II-4.4.4/src/sql/pgpool-regclass make & amp; & amp; make install psql -h /data/pgdata/tmp -p 4567 -U postgres -f pgpool-regclass.sql template1 # The following test is not executed ln -s /root/pgpool-II-4.4.4//src/sql/pgpool-regclass/* /usr/local/postgres/lib/ # […]
How to enable threads and thread pools in Python
1. Obtaining the optimal number of threads: 1. Carry out performance stress testing by slowly increasing the number of users, and observe QPS (that is, the number of response requests per second, that is, the maximum throughput capacity.), and response time. 2. Calculate according to the formula: The optimal number of threads on the server […]