When we read from HDFS, we overread to pick up the next blocks header.
Doing this saves a seek as we move through the hfile; we save having to
do an explicit seek just to read the block header every time we need to
read the body. We used to read in the next header as part of the
current blocks buffer. This buffer was then what got persisted to
blockcache; so we were over-persisting: our block plus the next blocks'
header (33 bytes).
This patch undoes this over-persisting.
Removes support for version 1 blocks (0.2 was added in hbase-0.92.0).
Not needed any more.
There is an open question on whether checksums should be persisted
when caching. The code seems to say no but if cache is SSD backed or
backed by anything that does not do error correction, we'll want
checksums.
Adds loads of documentation.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/hfile/BlockType.java
(write) Add writing from a ByteBuff.
M hbase-common/src/main/java/org/apache/hadoop/hbase/nio/ByteBuff.java
(toString) Add one so ByteBuff looks like ByteBuffer when you click on
it in IDE
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlock.java
Remove support for version 1 blocks.
Cleaned up handling of metadata added when we serialize a block to
caches. Metadata is smaller now.
When we serialize (used when caching), do not persist the next blocks
header if present.
Removed a bunch of methods, a few of which had overlapping
functionality and others that exposed too much of our internals.
Also removed a bunch of constructors and unified the constructors we
had left over making them share a common init method.
Shutdown access to defines that should only be used internally here.
Renamed all to do w/ 'EXTRA' and 'extraSerialization' to instead talk
about metadata saved to caches; was unclear previously what EXTRA was
about.
Renamed static final declarations as all uppercase.
(readBlockDataInternal): Redid. Couldn't make sense of it previously.
Undid heavy-duty parse of header by constructing HFileBlock. Other
cleanups. Its 1/3rd the length it used to be. More to do in here.
M hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java
optimize Add doc on what is being optimized. Also, if a Get Scan, do not
optimize else we'll keep going after our row is DONE.
Another place to make use of the Get Scan fact is when we are DONE.. if
Get Scan, we can close out the scan.
M hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java
Add tests for Get Scans and optimize around block loading.
Summary:
Move the config keys to one place
Make Two different config keys. One for default, one for priority
Test Plan: unit tests
Differential Revision: https://reviews.facebook.net/D55575
Summary:
Currently WAL splitting is broken when a region has been opened multiple times in recent minutes.
Region open and region close write event markers to the wal. These markers should have the sequence id in them. However it is currently getting 1. That means that if a region has moved multiple times in the last few mins then multiple split log workers will try and create the recovered edits file for sequence id 1. One of the workers will fail and on failing they will delete the recovered edits. Causing all split wal attempts to fail.
We need to:
It appears that the close event with a sequence id of one is coming from region warm up.
This patch fixes that by making sure the close on warm up doesn't happen. Also splitting will ignore any of the events that are already in the logs.
Test Plan: Unit tests pass
Differential Revision: https://reviews.facebook.net/D55557
stack
Misty Stanley-Jones
tedyu
Enis Soztutar
Elliott Clark
Sean Busbey
Yu Li
Mikhail Antonov
Matteo Bertozzi
anoopsjohn
Andrew Purtell
Jonathan M Hsieh
Liu Shaohui
Ted Malaska
Gábor Lipták
Stephen Yuan Jiang