[HBASE-6852] SchemaMetrics.updateOnCacheHit costs too much while full scanning a table with all of its fields

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.94.0
• Fix Version/s: 0.94.3
• Component/s: metrics
• Labels: performance
• Hadoop Flags: Reviewed
• Assignee: Cheng Hao
• Reporter: Cheng Hao
• Created: 21/Sep/12 03:08
• Updated: 03/Dec/12 21:47
• Resolved: 02/Nov/12 18:13

Description

The SchemaMetrics.updateOnCacheHit costs too much while I am doing the full table scanning.
Here is the top 5 hotspots within regionserver while full scanning a table: (Sorry for the less-well-format)

CPU: Intel Westmere microarchitecture, speed 2.262e+06 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 5000000
samples % image name symbol name
-------------------------------------------------------------------------------
98447 13.4324 14033.jo void org.apache.hadoop.hbase.regionserver.metrics.SchemaMetrics.updateOnCacheHit(org.apache.hadoop.hbase.io.hfile.BlockType$BlockCategory, boolean)
98447 100.000 14033.jo void org.apache.hadoop.hbase.regionserver.metrics.SchemaMetrics.updateOnCacheHit(org.apache.hadoop.hbase.io.hfile.BlockType$BlockCategory, boolean) [self]
-------------------------------------------------------------------------------
45814 6.2510 14033.jo int org.apache.hadoop.hbase.KeyValue$KeyComparator.compareRows(byte[], int, int, byte[], int, int)
45814 100.000 14033.jo int org.apache.hadoop.hbase.KeyValue$KeyComparator.compareRows(byte[], int, int, byte[], int, int) [self]
-------------------------------------------------------------------------------
43523 5.9384 14033.jo boolean org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(org.apache.hadoop.hbase.KeyValue)
43523 100.000 14033.jo boolean org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(org.apache.hadoop.hbase.KeyValue) [self]
-------------------------------------------------------------------------------
42548 5.8054 14033.jo int org.apache.hadoop.hbase.KeyValue$KeyComparator.compare(byte[], int, int, byte[], int, int)
42548 100.000 14033.jo int org.apache.hadoop.hbase.KeyValue$KeyComparator.compare(byte[], int, int, byte[], int, int) [self]
-------------------------------------------------------------------------------
40572 5.5358 14033.jo int org.apache.hadoop.hbase.io.hfile.HFileBlockIndex$BlockIndexReader.binarySearchNonRootIndex(byte[], int, int, java.nio.ByteBuffer, org.apache.hadoop.io.RawComparator)~1
40572 100.000 14033.jo int org.apache.hadoop.hbase.io.hfile.HFileBlockIndex$BlockIndexReader.binarySearchNonRootIndex(byte[], int, int, java.nio.ByteBuffer, org.apache.hadoop.io.RawComparator)~1 [self]