If TeamCity server is started in build messages processor mode its functionality is reduced to only one feature - process real time data coming from the running builds.
As you can imagine The primary purpose of this mode was added to address needs of is to provide scalability option for really large installations, running several hundreds or even thousand of agents on a single server now and planning on expanding their installation in the future.
Several important notes about two-node configuration:
- at the moment build messages processor node handles all of the data produced by running builds (build logs, artifacts, statistic values), pre-processes it and stores in database
- in two-node installation, both main TeamCity server and build messages processor require access to the same data directory (which should be shared somehow if nodes are installed on separate machines) and to the same database
- URL where build messages processor operates should be accessible by the agents and main TeamCity server (occasionally main TeamCity server also communicates with build messages processor by HTTP)
At the moment build messages processor node does not support plugins.
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