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https://issues.apache.org/jira/browse/HBASE-2600?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13159616#comment-13159616
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[email protected] commented on HBASE-2600:
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src/main/java/org/apache/hadoop/hbase/HRegionInfo.java
<https://reviews.apache.org/r/2968/#comment7985>
Please ignore me.
- Alex
On 2011-11-29 23:00:08, Alex Newman wrote:
bq.
bq. -----------------------------------------------------------
bq. This is an automatically generated e-mail. To reply, visit:
bq. https://reviews.apache.org/r/2968/
bq. -----------------------------------------------------------
bq.
bq. (Updated 2011-11-29 23:00:08)
bq.
bq.
bq. Review request for hbase.
bq.
bq.
bq. Summary
bq. -------
bq.
bq. This is an idea that Ryan and I have been kicking around on and off for a
while now.
bq.
bq. If regionnames were made of tablename+endrow instead of
tablename+startrow, then in the metatables, doing a search for the region that
contains the wanted row, we'd just have to open a scanner using passed row and
the first row found by the scan would be that of the region we need (If
offlined parent, we'd have to scan to the next row).
bq.
bq. If we redid the meta tables in this format, we'd be using an access that
is natural to hbase, a scan as opposed to the perverse, expensive
getClosestRowBefore we currently have that has to walk backward in meta finding
a containing region.
bq.
bq. This issue is about changing the way we name regions.
bq.
bq. If we were using scans, prewarming client cache would be near costless (as
opposed to what we'll currently have to do which is first a getClosestRowBefore
and then a scan from the closestrowbefore forward).
bq.
bq. Converting to the new method, we'd have to run a migration on startup
changing the content in meta.
bq.
bq. Up to this, the randomid component of a region name has been the timestamp
of region creation. HBASE-2531 "32-bit encoding of regionnames waaaaaaayyyyy
too susceptible to hash clashes" proposes changing the randomid so that it
contains actual name of the directory in the filesystem that hosts the region.
If we had this in place, I think it would help with the migration to this new
way of doing the meta because as is, the region name in fs is a hash of
regionname... changing the format of the regionname would mean we generate a
different hash... so we'd need hbase-2531 to be in place before we could do
this change.
bq.
bq.
bq. This addresses bug hbase-2600.
bq. https://issues.apache.org/jira/browse/hbase-2600
bq.
bq.
bq. Diffs
bq. -----
bq.
bq. src/main/java/org/apache/hadoop/hbase/HConstants.java d22f50a
bq. src/main/java/org/apache/hadoop/hbase/HRegionInfo.java 0c1fa3f
bq. src/main/java/org/apache/hadoop/hbase/catalog/CatalogTracker.java
1c49dc5
bq. src/main/java/org/apache/hadoop/hbase/catalog/MetaReader.java e5e60a8
bq. src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java aa8512b
bq. src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java
6af1f82
bq. src/main/java/org/apache/hadoop/hbase/client/MetaScanner.java 4135e55
bq. src/main/java/org/apache/hadoop/hbase/client/MetaSearchRow.java
PRE-CREATION
bq. src/main/java/org/apache/hadoop/hbase/regionserver/SplitTransaction.java
08b7de3
bq. src/main/java/org/apache/hadoop/hbase/rest/RegionsResource.java bf85bc1
bq. src/main/java/org/apache/hadoop/hbase/rest/model/TableRegionModel.java
67e7a04
bq. src/main/resources/hbase-default.xml 7059c60
bq. src/test/java/org/apache/hadoop/hbase/HBaseTestingUtility.java 66d808f
bq. src/test/java/org/apache/hadoop/hbase/TestKeyValue.java 7af4db4
bq. src/test/java/org/apache/hadoop/hbase/client/TestAdmin.java 940d726
bq. src/test/java/org/apache/hadoop/hbase/coprocessor/TestClassLoading.java
b579b29
bq.
src/test/java/org/apache/hadoop/hbase/regionserver/TestGetClosestAtOrBefore.java
49bfc5a
bq. src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegionInfo.java
477e772
bq.
src/test/java/org/apache/hadoop/hbase/regionserver/TestSplitTransactionOnCluster.java
24903f3
bq. src/test/java/org/apache/hadoop/hbase/rest/TestStatusResource.java
4a8bb69
bq.
src/test/java/org/apache/hadoop/hbase/rest/model/TestTableRegionModel.java
60e0e41
bq. src/test/ruby/hbase/admin_test.rb 0c2672b
bq.
bq. Diff: https://reviews.apache.org/r/2968/diff
bq.
bq.
bq. Testing
bq. -------
bq.
bq.
bq. Thanks,
bq.
bq. Alex
bq.
bq.
> Change how we do meta tables; from tablename+STARTROW+randomid to instead,
> tablename+ENDROW+randomid
> ----------------------------------------------------------------------------------------------------
>
> Key: HBASE-2600
> URL: https://issues.apache.org/jira/browse/HBASE-2600
> Project: HBase
> Issue Type: Sub-task
> Reporter: stack
> Assignee: Alex Newman
>
> This is an idea that Ryan and I have been kicking around on and off for a
> while now.
> If regionnames were made of tablename+endrow instead of tablename+startrow,
> then in the metatables, doing a search for the region that contains the
> wanted row, we'd just have to open a scanner using passed row and the first
> row found by the scan would be that of the region we need (If offlined
> parent, we'd have to scan to the next row).
> If we redid the meta tables in this format, we'd be using an access that is
> natural to hbase, a scan as opposed to the perverse, expensive
> getClosestRowBefore we currently have that has to walk backward in meta
> finding a containing region.
> This issue is about changing the way we name regions.
> If we were using scans, prewarming client cache would be near costless (as
> opposed to what we'll currently have to do which is first a
> getClosestRowBefore and then a scan from the closestrowbefore forward).
> Converting to the new method, we'd have to run a migration on startup
> changing the content in meta.
> Up to this, the randomid component of a region name has been the timestamp of
> region creation. HBASE-2531 "32-bit encoding of regionnames waaaaaaayyyyy
> too susceptible to hash clashes" proposes changing the randomid so that it
> contains actual name of the directory in the filesystem that hosts the
> region. If we had this in place, I think it would help with the migration to
> this new way of doing the meta because as is, the region name in fs is a hash
> of regionname... changing the format of the regionname would mean we generate
> a different hash... so we'd need hbase-2531 to be in place before we could do
> this change.
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