This article describes the proposed change to the Map Server Manager mechanisms of Map Server pooling to allow for defining multiple Map Server pools.
When running multiple web services (15 or more) from a single server the memory usage on a MapSvr.exe can be large once all Service Sources are initalised leaving limited available memory to handle map requests sent to the web services. The only way to implement a large web service implementation is to spread web services across multiple servers. This is deemed costly by customers due to the costs associated with licensing Hexagon and third-party software on additional servers.
The Map Server Manager will be enhanced to manage more than one pool of Map Servers. Its contract shall be extended with a way to request a Map Server from a specific pool. If no pool specification is provided, the Default pool is selected. The Default pool always exists and is reflecting the traditional behavior of the Map Server Manager. Clients of the Map Server Manager (SDI Services and WMPS) will request a Map Server for processing, optionally providing the pool specification. This requires the clients to have knowledge of the pool they shall make use of. The services’ configuration needs to be extended to contain an optional element where administrators might bind a specific service instance with a selected Map Server pool.
WebMap Publisher based services (WFS, WMS, WMPS) may also obtain the pool assignment from the Service Source they use to obtain their WebMap Publisher metadata.
For proper diagnostics, the performance counters maintained by both the Map Server Manager and the Map Servers need to take the existence of multiple pools into account. This means that there need to be multiple instances of the performance counters including an aggregating one taking information from the whole WebMap installation.
The configuration of the proposed pooling mechanism shall be split into two areas:
Using the Administration Console’s Engines Management section concerning GeoMedia WebMap’s System Settings. Currently there are setting for a single Map Server pool, whereas the change proposed calls for having the ability to add the same group of settings and naming them, thus creating Map Server pools:
The assignment to a given Map Server pool can be configured in two places:
With the assumption that setting (1) overrides (2) which overrides the default assignment to the Default Map Server Pool