8.5. HBase

This tab covers HBase settings. Here you can set properties for the HBase Master and RegionServer, as well as some general and advanced properties. Click the name of the group to expand and collapse the display.


Table 3.13. HBase Settings: HBase Master

HBase Master hostThis value is prepopulated based on your choices on previous screens

 HBase Master Maximum Java heap size

Maximum Java heap size for HBase master (Java option -Xmx)


Table 3.14. HBase Settings: RegionServer

RegionServer hostsThis value is prepopulated based on your choices on previous screens
 HBase Region Servers maximum Java heap size

Maximum Java heap size for HBase Region Servers (Java option -Xmx)

Important: For more information on sizing, see Recommended Memory Configurations for the MapReduce Service for recommended sizing.

HBase Region Server Handler

Count of RPC Listener instances spun up on RegionServers

HBase Region Major Compaction

The time between major compactions of all HStoreFiles in a region. Set to 0 to disable automated major compactions.

HBase Region Block MultiplierBlock updates if memstore reaches "Multiplier * HBase Region Memstore Flush Size" bytes. Useful preventing runaway memstore size during spikes in update traffic
HBase Region Memstore Flush Size

Memstore will be flushed to disk if size of the memstore exceeds this number of bytes.


Table 3.15. HBase Settings: General


HBase HStore compaction threshold

When HStoreFiles in any one HStore are greater than this number, a compaction is run to rewrite all HStoreFiles files as one.

HFile block cache size

Percentage of maximum heap (-Xmx setting) to allocate to block cache used by HFile/StoreFile. You can set this to 0 to disable but this is not a recommended practice.

Maximum HStoreFile Size

If any one of a column families' HStoreFiles has grown to exceed this value, the hosting HRegion is split in two.

HBase Client Scanner Caching

Number of rows that will be fetched when calling next on a scanner if it is not served from (local, client) memory. Do not set this value such that the time between invocations is greater than the scanner timeout

Zookeeper timeout for HBase Session

HBase passes this to the zk quorum as suggested maximum time for a session.

HBase Client Maximum key-value Size

Specifies the combined maximum allowed size of a KeyValue instance. It should be set to a fraction of the maximum region size.


Table 3.16. HBase Settings: Advanced

HBase Log Dir Directory for HBase logs
HBase PID DirDirectory for the PID files for HBase processes
HDFS Short-circuit read Check to enable
HDFS shortcircuit skip checksum Skip checksum for short-circuit read. Check to enable
HDFS append support Check to enable
hstore blocking storefiles If more than this number of StoreFiles in any one Store (one StoreFile is written per flush of MemStore), then updates are blocked in this HRegion until compaction is completed or until hbase.hstore.blockingWaitTime is exceeded.
hbase.master.lease.thread.wakefrequency The interval between checks for the expired region server leases. The default is 15 seconds but may be reduced so that the master notices a dead RegionServer more quickly.
hbase.superuserComma-separated list of users who are allowed full privileges across the cluster, regardless of stored ACLs. Used only when HBase security is enabled.
hbase.regionserver.optionalcacheflushinterval Amount of time to wait since the last time a region was flushed before invoking an optional cache flush. Default is 60,000.
Custom HBase Configs Use this text box to enter values for hbase-site.xml properties not exposed by the UI. Enter in "key=value" format, with a newline as a delimiter between pairs.

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