Problem: A subscriber receiving data through a stream does not receive all the data sent by the publisher before the ESP node shuts down unexpectedly.
Replace the stream feeding the subscriber with a window configured with a retention time long enough to allow the subscriber to reconnect when the node comes back up or (if the node is in active-active HA mode) fails over to its secondary instance. For example, if it takes the subscriber a minute to reconnect, you might configure a 2-minute retention time to ensure that no data is lost.
See the Programmers Guide or the Studio Users Guide for information on data retention policies for windows.
Replace the stream feeding the subscriber with a window on which guaranteed delivery (GD) is enabled.
Guaranteed delivery (GD) uses log stores to ensure that a GD subscriber registered with a GD window receives all the data processed by that window even if the client is not connected when the data is produced. GD is supported only on windows (not on streams or delta streams) and each GD window requires a log store.
For a window assigned to a memory store, a stream, or a delta stream, consider using persistent subscribe pattern (PSP) instead of GD.
See the Programmers Guide or the Studio Users Guide for information on guaranteed delivery. See the Studio Users Guide for information on PSP.