Druid Historical Configure

Tuning

Druid Historicals and MiddleManagers serve queries and can be co-located on the same hardware. Both Druid processes benefit greatly from being tuned to the hardware they run on. If you are running Tranquility Server or Kafka, you can also colocate Tranquility with these two Druid processes. If you are using r3.2xlarge EC2 instances, or similar hardware, the configuration in the distribution is a reasonable starting point.

If you are using different hardware, we recommend adjusting configurations for your specific hardware. The most commonly adjusted configurations are:

• -Xmx and -Xms
• druid.server.http.numThreads
• druid.processing.buffer.sizeBytes
• druid.processing.numThreads
• druid.query.groupBy.maxIntermediateRows
• druid.query.groupBy.maxResults
• druid.server.maxSize and druid.segmentCache.locations on Historical Nodes
• druid.worker.capacity on MiddleManagers

Example

{
  "jvm": {
    "xms": "8g",
    "xmx": "8g"
  }
}

module.exports = (service) ->
  options = service.options

Identity

  options.group ?= merge {}, service.deps.druid.options.user, options.group
  options.user ?= merge {}, service.deps.druid.options.user, options.user

Environment

  # Layout
  options.dir = service.deps.druid.options.dir
  options.log_dir = service.deps.druid.options.log_dir
  options.pid_dir = service.deps.druid.options.pid_dir
  options.hadoop_conf_dir = service.deps.hdfs_client.options.conf_dir
  # Miscs
  options.version ?= service.deps.druid.options.version
  options.timezone ?= service.deps.druid.options.timezone
  options.iptables ?= service.deps.iptables and service.deps.iptables.options.action is 'start'
  options.clean_logs ?= false

Java

  options.jvm ?= {}
  options.jvm.xms ?= '8g'
  options.jvm.xmx ?= '8g'
  options.jvm.max_direct_memory_size ?= options.jvm.xmx # Default is 4G

Configuration

  options.runtime ?= {}
  options.runtime['druid.service'] ?= 'druid/historical'
  options.runtime['druid.port'] ?= '8083'
  options.runtime['druid.server.http.numThreads'] ?= '25'
  options.runtime['druid.segmentCache.locations'] ?= '[{"path":"var/druid/segment-cache","maxSize"\:130000000000}]'
  options.runtime['druid.server.maxSize'] ?= '130000000000'

Processing

The broker uses processing configs for nested groupBy queries. And, optionally, Long-interval queries (of any type) can be broken into shorter interval queries and processed in parallel inside this thread pool. For more details, see "chunkPeriod" in Query Context doc.

• druid.processing.buffer.sizeBytes This specifies a buffer size for the storage of intermediate results. The computation engine in both the Historical and Realtime nodes will use a scratch buffer of this size to do all of their intermediate computations off-heap. Larger values allow for more aggregations in a single pass over the data while smaller values can require more passes depending on the query that is being executed. Default is "1073741824 (1GB)".
• druid.processing.numMergeBuffers: The number of direct memory buffers available for merging query results. The buffers are sized by druid.processing.buffer.sizeBytes. This property is effectively a concurrency limit for queries that require merging buffers. If you are using any queries that require merge buffers (currently, just groupBy v2) then you should have at least two of these. Default is "max(2, druid.processing.numThreads / 4)".

maxDirectMemory > memoryNeeded
memoryNeeded = druid.processing.buffer.sizeBytes * (druid.processing.numMergeBuffers + druid.processing.numThreads + 1)

  # options.runtime['druid.processing.buffer.sizeBytes'] ?= '536870912'
  # options.runtime['druid.processing.numThreads'] ?= '7'
  # TODO, if buffer.sizeBytes and numThreads are provided, assert they fit within the xmx value

Kerberos

  options.krb5_service = merge {}, service.deps.druid.options.krb5_service, options.krb5_service

Wait

  options.wait_krb5_client ?= service.deps.krb5_client.options.wait
  options.wait_zookeeper_server ?= service.deps.zookeeper_server[0].options.wait
  options.wait_hdfs_nn ?= service.deps.hdfs_nn[0].options.wait
  options.wait_druid_coordinator ?= service.deps.druid_coordinator[0].options.wait
  options.wait_druid_overlord ?= service.deps.druid_overlord[0].options.wait
  options.wait = {}
  options.wait.tcp = for srv in service.deps.druid_historical
    host: srv.node.fqdn
    port: srv.options.runtime?['druid.port'] or '8083'

Dependencies

{merge} = require '@nikitajs/core/lib/misc'