IndexPool MBean
The IndexPool MBean exposes metrics around the progress of indexing tasks as they move through the pipeline, and provides a mechanism to tweak the flushing, concurrency, and back-pressure behavior of a core indexing thread pool.
The IndexPool MBean is useful for controlling task submission and flush with these properties:
- Configurable concurrency
-
The maximum number of concurrent workers is predefined at construction time. The actual concurrency can be dynamically configured between 1 (synchronous execution) and the given max concurrency.
- Flow control via back pressure
-
To reduce memory consumption in case of fast producers, back pressure throttles incoming tasks. Back-pressure is applied directly as a result of the size of the global RAM buffer.
Path
The IndexPool MBean is identified by the following path:
com.datastax.bdp.search.KEYSPACE_NAME.TABLE_NAME.IndexPoolwhere:
-
searchis the MBean type -
KEYSPACE_NAME.TABLE_NAMEis the search index (core) that the metrics reference -
IndexPoolis the MBean name
Configurable attributes
The attributes are effective only until the node is restarted.
To make the change permanent, you must change the corresponding option in dse.yaml.
Where is the dse.yaml file?
The location of the dse.yaml file depends on the type of installation:
| Installation Type | Location |
|---|---|
Package installations + Installer-Services installations |
|
Tarball installations + Installer-No Services installations |
|
- FlushMaxTime
-
The maximum time, in milliseconds, to wait before flushing asynchronous index updates, which occurs at DSE Search commit time or at database flush time. See the
flush_max_time_per_coreoption indse.yaml. - Concurrency
-
The maximum number of concurrent asynchronous indexing threads.
View-only attributes
You can get the following MBean operations:
- BackPressurePauseNanos
-
Get the average back pressure pause.
- IncomingRate
-
Get the 1-minute rate of ingested tasks per second.
- MaxConcurrency
-
Get the predefined max concurrency level.
- OutgoingRate
-
Get the 1-minute rate of processed tasks per second.
- ProcessedTasks
-
Get the total number of processed tasks for all workers.
- QueueSize
-
Get the current size of each processing queues.
- TaskProcessingTimeNanos
-
Get the last processing time for all workers. Could be 0 in case the clock resolution is too coarse.
- Throughput
-
The 1-minute rate of work throughput per second.
- TotalQueueSize
-
Get the total size of all processing queues.
