English to Malay Tech/Engineering Computers (general) ICT

A "Connection Storm" is a behaviour that could be seen in large production environments as a result of a slowndown in the app server or database layers.

It happens like this: Let's say your site has 50 servers, each configured with 30 Web Container threads. On a typical day, the JVMs never have more than 8 active threads at any given time, and each server maintains in average 10 connections to the database.

Now there is a slowdown, which can be either on the database or the WebSphere Commerce JVMs. For this example, let's assume the problem is with a 3rd party Web Service that suddenly becomes slower than usual. As requests are taking longer to complete, new requests that come in need to use a new WebContainer thread, and also the DataSource must acquire a new connection from the Database for the thread. This could happen in a very short period of time until the WebContainer pool hits max and it is completely in use.

Before the slow down, the database had 500 established connections (50 JVMs x 10 connections). Now with the JVMs' WebContainer pool completely saturated, the number of connections surged all the way to 1,500 ( 50 JVMs * 30 WebContainer threads = Connections). The delta is 1,000 new connections created during the event. This is what we call "Connection storm".