Author: Zhiqiu Kong
Summary:
Added two separate metrics for both get() and next(). This is done by
refactoring on internal next() API. To be more specific, only Get.get()
and ResultScanner.next() passes the metric name ("getsize" and
"nextsize" repectively) to
HRegion::RegionScanner::next(List<KeyValue>, String)
This will eventually hit StoreScanner()::next((List<KeyValue>,
int, String) where the metrics are counted.
And their call paths are:
1) Get
HTable::get(final Get get)
=> HRegionServer::get(byte [] regionName, Get get)
=> HRegion::get(final Get get, final Integer lockid)
=> HRegion::get(final Get get) [pass METRIC_GETSIZE to the
callee]
=> HRegion::RegionScanner::next(List<KeyValue> outResults, String
metric)
=> HRegion::RegionScanner::next(List<KeyValue> outResults, int limit,
String metric)
=> HRegion::RegionScanner::nextInternal(int limit, String metric)
=> KeyValueHeap::next(List<KeyValue> result, int limit, String
metric)
=> StoreScanner::next(List<KeyValue> outResult, int limit, String
metric)
2) Next
HTable::ClientScanner::next()
=> ScannerCallable::call()
=> HRegionServer::next(long scannerId)
=> HRegionServer::next(final long scannerId, int nbRows) [pass
METRIC_NEXTSIZE to the callee]
=> HRegion::RegionScanner::next(List<KeyValue> outResults, String
metric)
=> HRegion::RegionScanner::next(List<KeyValue> outResults, int limit,
String metric)
=> HRegion::RegionScanner::nextInternal(int limit, String metric)
=> KeyValueHeap::next(List<KeyValue> result, int limit, String
metric)
=> StoreScanner::next(List<KeyValue> outResult, int limit, String
metric)
Test Plan:
1. Passed unit tests.
2. Created a testcase TestRegionServerMetrics::testGetNextSize to
guarantee:
* Get/Next contributes to getsize/nextsize metrics
* Both getsize/nextsize are per Column Family
* Flush/compaction won't affect these two metrics
Reviewed By: mbautin
Reviewers: Kannan, mbautin, Liyin, JIRA
CC: Kannan, mbautin, Liyin, zhiqiu
Differential Revision: https://reviews.facebook.net/D1617
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1299147 13f79535-47bb-0310-9956-ffa450edef68
Author: Zhiqiu Kong
Summary:
The original 89-fb diff is: https://reviews.facebook.net/D1263
Slow opertaion log does not provide enough information when a filter is
present. The followings are done to add the filter info:
1) Added toString() method for filters inheriting FilterBase, this
affect 22 filters and their subclasses. The info added includes the
filter's name and its members. For example, for TimestampsFilter, we'll
output its class name as well as the defined timestamps.
2) Added a field 'filter' in Get::toMap() and Scan::toMap() to enable
the logging of filter info.
Task ID: #750975
Blame Rev:
Test Plan:
1. Run and passed unit-tests to make sure it does not break things
2. Run kannan's script to trigger the slow operation logging, checked
for each filter to make sure the filter info was logged. To be more
detailed, the output log are as following (only 'filter' filed is put
here for ease of reading):
"filter":"TimestampsFilter (3/3): [2, 3, 5]"
"filter":"TimestampsFilter (5/6): [2, 3, 5, 7, 11]"
"filter":"ColumnPrefixFilter col2"
"filter":"ColumnRangeFilter [col2a, col2b]"
"filter":"ColumnCountGetFilter 8"
"filter":"ColumnPaginationFilter (4, 4)"
"filter":"InclusiveStopFilter row"
"filter":"PrefixFilter row"
"filter":"PageFilter 1"
"filter":"SkipFilter TimestampsFilter (1/1): [1000]"
"filter":"WhileMatchFilter TimestampsFilter (3/3): [2, 3, 5]"
"filter":"KeyOnlyFilter"
"filter":"FirstKeyOnlyFilter"
"filter":"MultipleColumnPrefixFilter (3/3): [a, b, c]"
"filter":"DependentColumnFilter (family, qualifier, true, LESS, value)"
"filter":"FamilyFilter (LESS, value)"
"filter":"QualifierFilter (LESS, value)"
"filter":"RowFilter (LESS, value)"
"filter":"ValueFilter (LESS, value)"
"filter":"KeyOnlyFilter"
"filter":"FirstKeyOnlyFilter"
"filter":"SingleColumnValueFilter (family, qualifier, EQUAL, value)"
"filter":"SingleColumnValueExcludeFilter (family, qualifier, EQUAL,
value)"
"filter":"FilterList AND (2/2): [KeyOnlyFilter, FirstKeyOnlyFilter]"
Please check ~zhiqiu/Codes/scripts/testFilter.rb for the testing script.
3. Added unit test cases to TestOperation to verify the filters'
toString() method works well.
Reviewed By: mbautin
Reviewers: Kannan, madhuvaidya, mbautin, JIRA
CC: Kannan, madhuvaidya, mbautin, zhiqiu, stack
Differential Revision: https://reviews.facebook.net/D1539
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1299019 13f79535-47bb-0310-9956-ffa450edef68
Author: Dhruba
Summary:
HFile is enhanced to store a checksum for each block. HDFS checksum verification
is avoided while reading data into the block cache. On a checksum verification
failure, we retry the file system read request with hdfs checksums switched on
(thanks Todd).
I have a benchmark that shows that it reduces iops on the disk by about 40%. In
this experiment, the entire memory on the regionserver is allocated to the
regionserver's jvm and the OS buffer cache size is negligible. I also measured
negligible (<5%) additional cpu usage while using hbase-level checksums.
The salient points of this patch:
1. Each hfile's trailer used to have a 4 byte version number. I enhanced this so
that these 4 bytes can be interpreted as a (major version number, minor
version). Pre-existing hfiles have a minor version of 0. The new hfile format
has a minor version of 1 (thanks Mikhail). The hfile major version remains
unchanged at 2. The reason I did not introduce a new major version number is
because the code changes needed to store/read checksums do not differ much from
existing V2 writers/readers.
2. Introduced a HFileSystem object which is a encapsulates the FileSystem
objects needed to access data from hfiles and hlogs. HDFS FileSystem objects
already had the ability to switch off checksum verifications for reads.
3. The majority of the code changes are located in hbase.io.hfie package. The
retry of a read on an initial checksum failure occurs inside the hbase.io.hfile
package itself. The code changes to hbase.regionserver package are minor.
4. The format of a hfileblock is the header followed by the data followed by the
checksum(s). Each 16 K (configurable) size of data has a 4 byte checksum. The
hfileblock header has two additional fields: a 4 byte value to store the
bytesPerChecksum and a 4 byte value to store the size of the user data
(excluding the checksum data). This is well explained in the associated
javadocs.
5. I added a test to test backward compatibility. I will be writing more unit
tests that triggers checksum verification failures aggressively. I have left a
few redundant log messages in the code (just for easier debugging) and will
remove them in later stage of this patch. I will also be adding metrics on
number of checksum verification failures/success in a later version of this
diff.
6. By default, hbase-level checksums are switched on and hdfs level checksums
are switched off for hfile-reads. No changes to Hlog code path here.
Test Plan: The default setting is to switch on hbase checksums for hfile-reads,
thus all existing tests actually validate the new code pieces. I will be writing
more unit tests for triggering checksum verification failures.
Reviewers: mbautin
Reviewed By: mbautin
CC: JIRA, tedyu, mbautin, dhruba, todd, stack
Differential Revision: https://reviews.facebook.net/D1521
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1298641 13f79535-47bb-0310-9956-ffa450edef68
Michael Stack
mbautin
Zhihong Yu
larsh
Andrew Kyle Purtell
ramkrishna
Doug Meil