Monitor Server collects information from two sources in Adaptive Server shared memory space:
Counters collect information at a high level, such as the number of times a certain activity occurs server-wide or per engine or per database device.
Events are data structures in Adaptive Server shared memory containing detailed information about activities in Adaptive Server. Monitor Server collects information from these events and summarizes it. Monitor Server maintains event summaries at a level of detail specified by its clients.
Monitor Server allocates the following internal buffers in heap space to hold this information:
For each client connection, when the connection initially occurs, Monitor Server allocates a small buffer to hold a snapshot of counter values before the values are sent to the client.
For each event summary request enabled over a client connection, Monitor Server allocates a summary buffer. If a summary buffer fills up, Monitor Server allocates additional buffers dynamically. The size and number of these buffers are controlled by three Monitor Server configuration parameters:
bufsize controls the size of each summary buffer
max_mem_blks controls how many buffers may be allocated for each event summary request
max_summaries controls how many event summaries may be requested by each client connection
The amount of heap space per summary buffer is typically 32KB, but it can vary with the volume of data encountered. There is a risk that, if the Monitor Server uses too much heap space, its heap will collide with the location at which Adaptive Server shared memory is attached. In that case, you should reconfigure and reboot Adaptive Server so that it uses a higher virtual memory starting address, which allows Monitor Server to do the same. This effectively provides more heap space to Monitor Server.