To use these, append the following to your configuration file. While the values you set will vary depending on your traffic load and environment, I’ve listed the most common configurations below. If you want to take it up a notch, there are other timeout settings you can set to enhance performance. Just by configuring these three timeout values in your haproxy.cfg file, you can achieve a basic level of performance. You can see in the list of HTTP responses, if a is invoked, you’ll get a 504 Gateway Timeout response from HAProxy. If the server doesn’t respond in the configured time duration, a is invoked. When a client sends a request to the server, it expects a response. The default is three, but you can adjust it to fit your environment. In addition to the connection time, you’ll need to set the numbers of retries. The timeout connect allows the client to try to connect again if the initial attempt fails. The more complex a topology, the longer it can take the client to connect. The time it takes a client to connect to a server varies widely, depending on network complexity. It sets the maximum time the client has to connect to a server. As the name suggests, this timeout is handled on the client side. You can go with shorter timeouts, even as little as thirty seconds, if you’re attempting to maximize security or the total number of active connections. A common value for this timeout is five minutes. The setting defines the maximum time a client can be inactive when connected to the server. #based on Mesosphere Marathon’s servicerouter.py haproxy config Just to show you what timeout configurations look like, here’s a sample including the three basic timeouts. Let’s quickly cover the various types of timeouts before we get to the tuning part. It’s as if the stalled cars are taken off the road, so other cars can move freely. This frees up connections, so active users can access the application. Timeouts terminate connections after a client waits for a predetermined amount of time to access the server. This is where the concept of timeouts is essential to avoid jams. If you add enough vehicles, however, even these additional lanes will become congested. Additional lanes won’t increase speed but cars travel down the road without waiting for the car ahead to advance. More lanes mean more vehicles can now travel the road. Adding HAProxy as a load balancer, is like adding lanes to the road. When numerous users access the application at the same time, requests can back up and even overwhelm the application.Ī good analogy is a single-lane road going from point A to point B filling up when there are too many cars. Once the application gains traction and the number of users increases, you can see application performance begin to decline. This method works fine if the application doesn’t get much traffic. The image above shows the basic design of how users access web. This should help us visualize the “how” part later and understand why it’s worth going through the tuning processes. I’ll quickly go through some of the HAProxy timeout configurations to lay a foundation.īefore we dive into the overview, let’s go over a few reasons why we need HAProxy and the logic behind it. You’ll see how robust HAProxy logging can help you with troubleshooting timeout issues, and improve the performance of your application. I’m going to take you through the process of tuning timeouts with the intent to boost application performance. Through load balancing, HAProxy makes sure each service your application depends on is accessible to users, especially under load conditions otherwise impacting application performance. When configured correctly, HAProxy improves your app’s performance significantly. It’s ideally the first point of contact for users who access your application. When you get an unexpected HTTP Response code it's good to keep an eye on the web server too.HAProxy (high availability proxy) is a critical part of modern systems infrastructure. If you didn't set any response code from php, PHP returns 200 if everything is OK, 500 if error occured. if php max_execution_time is 120 sec, but TimeOut is 300 sec - your script will execute for max 120 seconds, but your connection can stay alive for 300 seconds.if php max_execution_time is 120 sec, but TimeOut is 30 sec - you will get a 504 error.While the max_execution_time in php.ini sets the execution time of php, the Apache TimeOut directive sets the maximum connection time. The web server will only keep the connection open for 60 seconds regardless the max_execution_time If using Apache Web Server 2.4, the TimeOut directive is by default set to 60 seconds. Notice: This solution is not recommended for production use or high traffic scenarios, make sure this action is performed on an isolated server. Here is the alternative if the above is not possible: The recommendation is to make more short calls to check status / retrieve data.
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