Tomcat server parameter analysis and high concurrency control in Spring Boot
Spring Boot integrates a variety of servers, and the Tomcat server is used by default. Under high concurrency conditions, reasonable configuration of Tomcat server parameters is crucial to control the request volume and improve system stability. This article will explain some key parameters involving the Tomcat server in Spring Boot, and explore how to control the request volume through these parameters in high concurrency situations.
1. server.port
This parameter is used to specify the port number that the server listens on. By configuring different port numbers, multiple services can run in parallel on the same host.
2. server.tomcat.threads.max
This parameter defines the maximum number of threads for the Tomcat server. In high concurrency situations, you can increase the server's ability to process requests by increasing the maximum number of threads, but you need to pay attention to the server's hardware resource limitations.
3. server.tomcat.threads.min-spare
This parameter is used to set the minimum number of threads that the server maintains in an idle state. Make sure the server has enough threads available when processing requests to avoid delays.
4. server.tomcat.maxConnections
This parameter specifies the maximum number of connections that the server accepts and handles. After this limit is exceeded, the operating system may still accept connections, but limit the number of connections based on the "acceptCount" property.
5. server.tomcat.acceptCount
This parameter defines the maximum queue length for incoming connection requests when all possible request handling threads are in use. In high concurrency situations, you can control the queue length of connection requests by appropriately adjusting this parameter.
6. server.tomcat.connectionTimeout.seconds
The connection timeout indicates the maximum time the server waits for a connection request. In high-concurrency scenarios, setting an appropriate connection timeout can optimize connection management and avoid resource waste.
7. server.tomcat.maxKeepAliveRequests
This parameter specifies the maximum number of HTTP requests that can be transmitted over a persistent connection (Keep-Alive). In high concurrency situations, you can optimize the use of server resources by limiting the number of requests on each connection.
Analogy to Java Thread Pool
There is a certain analogy between configuring Tomcat server parameters in Spring Boot and Java thread pool technology. We can compare the parameters in Tomcat with the related concepts of Java thread pool to help better understand the role of these parameters in high concurrency scenarios.
1. server.tomcat.threads.maxMaximum number of threads with thread pool
server.tomcat.threads.maxThe parameter is analogous to the maximum number of threads in the thread pool. Just like the maximum number of threads that can be accommodated in the thread pool, the Tomcat server also has a limit on the maximum number of threads it can handle requests.
2. server.tomcat.threads.min-spareMinimum number of idle threads and thread pool
server.tomcat.threads.min-spareThe parameter is equivalent to the minimum number of idle threads in the thread pool. They all ensure that the server or thread pool can respond to requests immediately when needed, avoiding the delay caused by creating new threads.
3. server.tomcat.maxConnectionsMaximum number of connections to the thread pool
server.tomcat.maxConnectionsThe parameter is analogous to the maximum number of connections in the thread pool. They both define the maximum number of request connections that can be handled simultaneously.
4. server.tomcat.acceptCountWaiting queue with thread pool
server.tomcat.acceptCountThe parameters are analogous to the waiting queue of the thread pool. When all threads are in use, new connection requests will be placed in the waiting queue, waiting for processing by idle threads.
5. server.tomcat.processorCacheThread cache with thread pool
server.tomcat.processorCacheThe parameters are analogous to the thread cache of the thread pool. They are all designed to reuse idle processing threads when requests arrive to improve processing efficiency.
6. server.tomcat.connectionTimeout.secondsSettings with connection timeout
server.tomcat.connectionTimeout.secondsThe parameters are analogous to the task execution timeout in the thread pool. They all specify the maximum time to wait for a connection or task to avoid long waits.
7. server.tomcat.keepAliveTimeout.secondsAnd keep-alive time
server.tomcat.keepAliveTimeout.secondsThe parameter is analogous to the thread keep-alive time in the thread pool. They all determine how long a thread or connection remains active when there are no new tasks.
8. server.tomcat.maxKeepAliveRequestsKeep active with the maximum number of requests
server.tomcat.maxKeepAliveRequestsThe parameter is analogous to the maximum number of tasks that can be kept active in the thread pool. They all limit the number of requests that remain active to avoid excessive resource usage.
Through these analogies, you can more intuitively understand the role of configuring Tomcat server parameters in Spring Boot and its association with Java thread pool technology. Properly configuring these parameters can optimize server performance, effectively control the number of requests in high concurrency scenarios, and improve system stability.
What is the difference between the two parameters server.tomcat.maxConnections and server.tomcat.acceptCount?
server.tomcat.maxConnections and server.tomcat.acceptCount are two parameters related to Tomcat server connection management, used to control the maximum number of connections of the server and the maximum queue length of connection requests.
server.tomcat.maxConnections:
server.tomcat.maxConnections defines the maximum number of connections accepted and processed by the server. Once this number of connections is reached, the server will no longer accept new connections. After this limit is exceeded, new connections will be rejected by the operating system or queued, depending on the operating system settings.
server.tomcat.acceptCount:
The server.tomcat.acceptCount parameter defines the maximum queue length for incoming connection requests when all possible request processing threads are in use. When processing threads are occupied, new connection requests are queued until a processing thread becomes available. This parameter controls the maximum length of the queue. Requests exceeding this length will be rejected.
Summary of differences:
server.tomcat.maxConnections controls the maximum number of connections that the server can handle, including established connections and connections that are queued.
server.tomcat.acceptCount controls the maximum number of connections queued for processing, that is, the number of connections allowed to be queued when all possible request processing threads are in use.
In high concurrency situations, setting these two parameters appropriately can optimize the server's connection management, ensure that the system can handle connection requests normally under high load, and avoid system crashes or overload operation.
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