Configuring When the WQS/WIS Shared Memory is Written to the Database

The WQS/WIS shared memory cache holds summary information about work queues, such as which WIS process is handling a queue, how many work items it contains, how many new items, items with deadlines, and so on. This information is constantly updated by the WQS and WIS processes.

The shared memory persistence thread wakes up every WQS_PERSIST_SHMEM seconds and writes the contents of the WQS/WIS shared memory to the wqs_index database table.

When the WIS process starts up, it needs to know how many work items are in each queue that it is handling, so that it can determine whether or not to cache the queue immediately (see Configuring When WIS Processes Cache Their Queues). The WIS process can therefore read this information from the total_items column in the wqs_index database table.