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Broker Node Configuration
For general Broker Node information, see here.
Runtime Configuration
The broker module uses several of the default modules in Configuration and has the following set of configurations as well:
| Property | Possible Values | Description | Default |
|---|
druid.broker.cache.type | local, memcached | The type of cache to use for queries. | local |
druid.broker.balancer.type | random, connectionCount | Determines how the broker balances connections to historical nodes. random choose randomly, connectionCount picks the node with the fewest number of active connections to | random |
Local Cache
| Property | Description | Default |
|---|
druid.broker.cache.sizeInBytes | Maximum cache size in bytes. Zero disables caching. | 0 |
druid.broker.cache.initialSize | Initial size of the hashtable backing the cache. | 500000 |
druid.broker.cache.logEvictionCount | If non-zero, log cache eviction every logEvictionCount items. | 0 |
Memcache
| Property | Description | Default |
|---|
druid.broker.cache.expiration | Memcached expiration time. | 2592000 (30 days) |
druid.broker.cache.timeout | Maximum time in milliseconds to wait for a response from Memcached. | 500 |
druid.broker.cache.hosts | Command separated list of Memcached hosts <host:port>. | none |
druid.broker.cache.maxObjectSize | Maximum object size in bytes for a Memcached object. | 52428800 (50 MB) |
druid.broker.cache.memcachedPrefix | Key prefix for all keys in Memcached. | druid |