Among other things, processing an incoming message stream includes storing context data of an application in a global database. Various messages from the incoming message stream are placed in an in-memory message queue. One of at least a first and a second phases at a first process is executed, and another of the at least first and second phases at a second process is also executed, so as to alternately execute a first phase and a second phase by a first process and a second process. The first phase includes processing at least one message from the various messages and storing at least one corresponding result in a local memory area. The first phase also includes storing at least one modification to the context data in the local memory area. The second phase includes performing a transaction of the at least one result and the at least one modification of the context data to the global database and committing the transaction.