SSE Mode Properties

By default, the Change Log Daemon works by polling Content Store change log endpoints at intervals. You can, however optionally configure the Change Log Daemon Server-Sent Events (SSE) instead:

enableSSE=true

If you do this, then you can control various aspects of how SSE is used by setting the following additional properties:

SSEReconnectInterval

When running in SSE mode, the initial number of seconds to wait after a connection loss before reconnecting to the Content Store. If the reconnection attempt fails then the Change Log Daemon backs off by waiting twice as long before it makes another attempt. The interval keeps being doubled until either a connection is established or maxReconnectInterval (see below) is reached. The default value is 10 seconds.

SSEMaxReconnectInterval

A maximum size for SSEReconnectInterval. The default value is 60 seconds. If a connection fails and cannot be re-established, then by default SSEReconnectInterval will increase in size as follows: 10, 20, 40, 60, 60, ... etc.

SSEInactivityThreshold

In some cases it is possible for a Content Store connection to fail without the Change Log Daemon being informed. This parameter makes it possible to recover from such situations. If a Content Store endpoint is silent for longer than the specified threshold, then the connection is assumed to be broken. The Change Log Daemon then terminates the connection and starts a new one. The default value is 600 seconds (that is, 10 minutes).

SSEPollInterval

This is the change log poll interval to use when SSE is enabled. In general, polling should not be necessary when SSE is enabled so this property should be set to a very high value. If this interval elapses with no events, then the Change Log Daemon will poll the change log anyway. The default value is 600 seconds (that is, 10 minutes).

SSEMSecsBeforeRead

Actions taken in CUE (creating a new content item, for example) can result in a stream of SSE events. In order to prevent each one of those events triggering a Change Log Daemon read action, you can use this property to configure a small delay, specified in milliseconds. This prevents the Change Log Daemon accessing the change log many times in response to a single user-level event. The default value is 50 milliseconds.

SSEMSecsBetweenReads

This property sets the minimum time that must elapse between Change Log Daemon read actions. Once the Change Log Daemon has accessed the change log it cannot do so again until this interval has elapsed. The default value is 1000 milliseconds.

You should set these properties to the same value in all your change log daemons. Specifying different values in different daemons will increase the number of SSE worker threads.