Enable stateful functions
When the stateful APIs of Pulsar Functions are required – for example, putState()
and queryState()
related interfaces – you need to enable the stateful function feature in function workers.
To enable the stateful function feature in function workers, complete the following steps.
Enable the
streamStorage
service in BookKeeper. Currently, the service uses the NAR package, so you need to set the configuration in theconf/bookkeeper.conf
file.##################################################################
##################################################################
# Settings below are used by stream/table service
##################################################################
##################################################################
### Grpc Server ###
# the grpc server port to listen on. default is 4181
storageserver.grpc.port=4181
### Dlog Settings for table service ###
#### Replication Settings
dlog.bkcEnsembleSize=3
dlog.bkcWriteQuorumSize=2
dlog.bkcAckQuorumSize=2
### Storage ###
# local storage directories for storing table ranges data (e.g. rocksdb sst files)
storage.range.store.dirs=data/bookkeeper/ranges
# whether the storage server capable of serving readonly tables. default is false.
storage.serve.readonly.tables=false
# the cluster controller schedule interval, in milliseconds. default is 30 seconds.
storage.cluster.controller.schedule.interval.ms=30000After starting the bookie, use the following methods to check whether the
streamStorage
service has been started successfully.Input:
telnet localhost 4181
Output:
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Configure
stateStorageServiceUrl
in theconf/functions_worker.yml
file.bk-service-url
is the service URL pointing to the BookKeeper table service.stateStorageServiceUrl: bk://<bk-service-url>:4181