id: version-0.20.0-incubating-cluster-config-stream title: Stream Manager sidebar_label: Stream Manager original_id: cluster-config-stream

You can configure the Stream Manager (SM) in a topology using the parameters below, including how the SM handles back pressure.

Back Pressure Parameters

ParameterMeaningDefault number of times the SM should wait to see a buffer full while enqueueing data before declaring the start of backpressure3 high water mark on the number of megabytes that can be left outstanding on a connection50 low water mark on the number of megabytes that can be left outstanding on a connection30 maximum packet size, in megabytes, for the SM's network options100

Timeout Interval


Other Parameters

heron.streammgr.packet.maximum.size.bytesMaximum size (in bytes) of packets sent out from the SM102400
heron.streammgr.cache.drain.frequency.msThe frequency (in milliseconds) at which the SM's tuple cache is drained10
heron.streammgr.cache.drain.size.mbThe size threshold (in megabytes) at which the SM's tuple cache is drained100
heron.streammgr.client.reconnect.interval.secThe reconnect interval to other SMs for the SM client (in seconds)1
heron.streammgr.client.reconnect.tmaster.interval.secThe reconnect interval to the Topology Master for the SM client (in seconds)10
heron.streammgr.tmaster.heartbeat.interval.secThe interval (in seconds) at which a heartbeat is sent to the Topology Master10 maximum batch size (in megabytes) at which the SM reads from the socket1
heron.streammgr.connection.write.batch.size.mbThe maximum batch size (in megabytes) to write by the stream manager to the socket1