some/ path/ to/ hbase- shaded- mapreduce. $> HADOOP_CLASSPATH=/ etc/ hbase/ conf: $( hbase mapredcp) yarn jar \ The default value is 0.5f, which means that half the files (the least-recently-used Which is triggered by reaching the `.size` threshold. The default value is 3600 seconds.Ī multiplier (between 0.0 and 1.0), which determines how many files remain cachedĪfter the threshold of files that remains cached after a cache eviction occurs The amount of time in seconds after which an unused file is evicted from the However, if this is set too high, this could lead to a "too many opened file handers"
TheĪ larger value will benefit reads by providing more file handlers per mobįile cache and would reduce frequent file opening and closing.
#Hbase archive cleaner code
Optionally,Ĭonfigure the MOB file reader’s cache settings for each RegionServer (seeĬonfiguring the MOB Cache), then configure specific columns to hold MOB data.Ĭlient code does not need to change to take advantage of HBase MOB support. To take advantage of MOB, you need to use HFile version 3. Provided by the work done in HBASE-11339. To maintain performance, consistency, and low operational overhead. HBase 2 added special internal handling of MOBs When using MOBs, ideally your objects will be betweenġ00KB and 10MB (see the ). HBase deals with large numbers of objects over this threshold, referred to hereĪs medium objects, or MOBs, performance is degraded due to write amplificationĬaused by splits and compactions. Read and write paths are optimized for values smaller than 100KB in size.
While HBase can technically handleīinary objects with cells that are larger than 100 KB in size, HBase’s normal Data comes in many sizes, and saving all of your data in HBase, including binaryĭata such as images and documents, is ideal.
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