Class GcpManagedChannelOptions.GcpChannelPoolOptions.Builder (1.17.0)

Disables dynamic scaling functionality. See Also: #setDynamicScaling(int, int, Duration)

How long to keep an affinity key after its last use. Zero value means keeping keys forever.

Sets the strategy for picking the least busy channel from the pool.

Defaults to ChannelPickStrategy#POWER_OF_TWO which avoids the thundering herd problem by sampling two channels with replacement and picking the less busy one. The first sample wins ties, with no channel-warmth preference. Inactive samples are retried.

Use ChannelPickStrategy#LINEAR_SCAN to restore the legacy behavior of scanning all channels and always picking the one with the lowest picker load.

Sets the maximum number of attempts to prime one scaled-up channel. Zero uses the default of 3. Retry backoff is exponential from 100 ms and capped at 5 s.

Sets the maximum time allowed for each channel-primer attempt, including the synchronous call to the primer. Zero uses the 10-second default.

Sets the optional hook that primes newly built scale-up channels concurrently. Only channels added by dynamic scale-up are primed; the initial pool and non-dynamic growth are published as soon as they are built. Each scale-up channel is published individually when its own primer future succeeds. A null primer disables priming and preserves the existing scale-up path.

How frequently affinity key cleanup process should run. Zero value disables cleanup process. If affinityKeyLifetime is not zero, this defaults to affinityKeyLifetime / 10.

Sets the concurrent streams low watermark. If every channel in the pool has at least this amount of concurrent streams then a new channel will be created in the pool unless the pool reached its maximum size.

Sets how long an idle draining channel remains open for sticky affinity references and in-flight calls before its delegate closes. Defaults to one minute.

Enables dynamic scaling functionality.

After a call is counted, load above maxRpcPerChannel on its selected channel or across the pool average signals a background scale-up worker.

Every scaleDownInterval, after consecutive low-load checks, the least-loaded channels are marked draining and removed from selection, bounded by maxScaleDownChannels; fewer affinity bindings and then older allocations break load ties. Draining channels receive no new picks or affinity binds and close after their in-flight calls reach zero and drainIdleGrace elapses. Scale-up always creates new channels.

Sets how long an applied penalty takes to decay linearly to zero. Each new retryable error resets the decay timer to a full window. Must be positive. Defaults to 5 seconds.

Sets the load penalty added after each retryable channel error. A value of 0 disables error penalties. Each step accumulates on the stored undecayed penalty, capped at maxRpcPerChannel. Must not be negative. Defaults to 5.

Sets the initial channel pool size. This is the number of channels that the pool will start with. If it is less than #setMinSize(int) it is ignored.

Sets the maximum percentage of active channels added by one scale-up operation. The percentage cap has a two-channel floor before desired-size and maximum-size clamps.

Sets the maximum size of the channel pool.

Sets the minimum size of the channel pool. This number of channels will be created and these channels will try to always keep connection to the server established.

Sets the minimum interval between successful scale-up operations. Zero uses the 10-second default.

Enables/disables using round-robin channel selection for affinity binding calls.