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Posted to dev@hbase.apache.org by Jonathan Gray <jg...@apache.org> on 2010/10/25 04:29:07 UTC
Review Request: Increment multiple columns in a row at once
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/
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Review request for hbase, stack and khemani.
Summary
-------
Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
This addresses bug HBASE-2946.
http://issues.apache.org/jira/browse/HBASE-2946
Diffs
-----
trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026930
trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026930
trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026930
Diff: http://review.cloudera.org/r/1088/diff
Testing
-------
Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
Thanks,
Jonathan
Re: Review Request: Increment multiple columns in a row at once
Posted by Ryan Rawson <ry...@gmail.com>.
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/#review1660
-----------------------------------------------------------
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
<http://review.cloudera.org/r/1088/#comment5541>
your logic is correct, and normally this is an issue, but there is this line a few down:
now = Math.max(now, kv.getTimestamp());
I havent played with the new sorting thing, the big problem is you get lost updates via ICV if things dont go right.
I just had a notion, when we do the 'get from memstore first' how do we handle duplicate TSs in snapshot and kvset... looking at the memstore scanner, i see this:
return getLower(kvsetNextRow,
snapshotNextRow);
and inside the implementation of getLower(), we return 'kvsetNextRow' when the two compare to the same. So it should be ok. If it doesn't work out, the worst case scenario is probably losing 1ms worth of updates.
- Ryan
On 2010-10-25 15:06:49, Jonathan Gray wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1088/
> -----------------------------------------------------------
>
> (Updated 2010-10-25 15:06:49)
>
>
> Review request for hbase, stack and khemani.
>
>
> Summary
> -------
>
> Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
>
> The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
>
> The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
>
>
> This addresses bug HBASE-2946.
> http://issues.apache.org/jira/browse/HBASE-2946
>
>
> Diffs
> -----
>
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
> trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026935
> trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026935
> trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026935
>
> Diff: http://review.cloudera.org/r/1088/diff
>
>
> Testing
> -------
>
> Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
>
>
> Thanks,
>
> Jonathan
>
>
Re: Review Request: Increment multiple columns in a row at once
Posted by Jonathan Gray <jg...@apache.org>.
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/
-----------------------------------------------------------
(Updated 2010-10-25 15:06:49.931026)
Review request for hbase, stack and khemani.
Changes
-------
Changes from Ryan and Prakash reviews.
We could use a nice test of this concurrent w/ snapshotting, flushing, etc... I don't have much time to do that now but would like to get this committed. It works in general and does not change anything in the existing incrementColumnValue call, it's only the Increment that skips the snapshot check.
Trying to get this committed so we can push it out to some clusters and start hammering it.
Summary
-------
Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
This addresses bug HBASE-2946.
http://issues.apache.org/jira/browse/HBASE-2946
Diffs (updated)
-----
trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026935
trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026935
trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026935
Diff: http://review.cloudera.org/r/1088/diff
Testing
-------
Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
Thanks,
Jonathan
Re: Review Request: Increment multiple columns in a row at once
Posted by Ryan Rawson <ry...@gmail.com>.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 495
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line495>
> >
> > yeah you cant compare against memstoreTS because if you have this in here you wont be able to ever increment values that were inserted into the future. you'd just leave them there and continually see it in the 'get' part and then in this code bit leave it in place and create a new KV that is masked by the future KV.
> >
> > It won't be possible for that insert to be part of an uncommitted change because of the rowlock however. So no atomic-rules will have been broken.
>
> Jonathan Gray wrote:
> i'm not sure i follow. am i doing it wrong? this should be exactly the same as what's there.
>
> also, we are breaking the atomic-rules across the Increment. Each column is not broken but across them it is (for reads not writes).
>
> It seems like we could use RWCC though for increments. I think it's fine that if you're using increment you can never write data into it w/ another API (or really, with manual timestamps).
there is no easy way to include RWCC right now, because you have to be careful about 'committing' the new values before removing the old ones. This is a bit tricky because normally the RWCC 'commit' happens at the HRegion level, and right now we are inside memstore/store. Hopefully people won't need atomic reads of multi incremented values. If one is doing counters this would be the case. Javadoc should definitely yell about this.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 377
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line377>
> >
> > I'm not sure how this code is optional for your new 'upsert', here are some use cases that I found painful:
> >
> > - when the KV is in snapshot we can create new KVs in memstore with the same TS. This means you have a dup and before we had this new 'dup' code it ruined counts badly.
> > - the Math.max() bit it to ensure the new KV isnt being created in the past a bit and accidently duplicating a timestamp inside the snapshot.
>
> Jonathan Gray wrote:
> what do you mean by optional? there shouldn't be any real difference. this code is basically the exact same code that was there but now pulled into a method that can be reused.
The original updateColumnValue code was structured like this:
- look in snapshot
- loop over kvset
Create new KV, insert it
- loop over kvset
But you only included the 2nd half. Your new 'upsert' only includes half the implementation of updateColumnValue.
This comes up in this scenario:
- increment at TS=100
- snapshot, now we have kvset={} and a KV, TS=100 in snapshot
- increment at TS=100
Without the code i have above we'll end up with 2 KVs, both of TS=100, one in kvset, one in snapshot, which then becomes a HFile.
When future reads happen, if they don't see the 'correct' KV, you will end up with lost updates.
In theory the 'read memstore first' and 'order duplicate TS KVs' patches should resolve this. Lost updates reallllllly suck though. I'd probably recommend the conservative course, because I already went thru this and it sucks. If you decide that you are willing to risk it, I might recommend this particular test case:
- increment some data at TS=X
- snapshot at TS=X
- increment some data at TS=X, now you have 2 * KV, TS=X
- flush to hfile
- increment at TS=X, ensure you dont lose any updates
- snapshot/flush with TS=X in kvset->snapshot->hfile
- compact the 2 hfiles both with TS=X in them
- do read and make sure the value is what you expect.
By using the manual environment edge you can control the currentTimeMillis() returned inside HRegion and down.
This covers the worst case scenario I think, since normally one would get increments and you shouldn't get TS=X * 2 in a single HFile.
- Ryan
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/#review1641
-----------------------------------------------------------
On 2010-10-24 19:29:07, Jonathan Gray wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1088/
> -----------------------------------------------------------
>
> (Updated 2010-10-24 19:29:07)
>
>
> Review request for hbase, stack and khemani.
>
>
> Summary
> -------
>
> Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
>
> The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
>
> The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
>
>
> This addresses bug HBASE-2946.
> http://issues.apache.org/jira/browse/HBASE-2946
>
>
> Diffs
> -----
>
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
> trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026930
> trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026930
>
> Diff: http://review.cloudera.org/r/1088/diff
>
>
> Testing
> -------
>
> Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
>
>
> Thanks,
>
> Jonathan
>
>
Re: Review Request: Increment multiple columns in a row at once
Posted by Jonathan Gray <jg...@apache.org>.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 377
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line377>
> >
> > I'm not sure how this code is optional for your new 'upsert', here are some use cases that I found painful:
> >
> > - when the KV is in snapshot we can create new KVs in memstore with the same TS. This means you have a dup and before we had this new 'dup' code it ruined counts badly.
> > - the Math.max() bit it to ensure the new KV isnt being created in the past a bit and accidently duplicating a timestamp inside the snapshot.
>
> Jonathan Gray wrote:
> what do you mean by optional? there shouldn't be any real difference. this code is basically the exact same code that was there but now pulled into a method that can be reused.
>
> Ryan Rawson wrote:
> The original updateColumnValue code was structured like this:
>
> - look in snapshot
> - loop over kvset
>
> Create new KV, insert it
>
> - loop over kvset
>
> But you only included the 2nd half. Your new 'upsert' only includes half the implementation of updateColumnValue.
>
> This comes up in this scenario:
>
> - increment at TS=100
> - snapshot, now we have kvset={} and a KV, TS=100 in snapshot
> - increment at TS=100
>
> Without the code i have above we'll end up with 2 KVs, both of TS=100, one in kvset, one in snapshot, which then becomes a HFile.
>
> When future reads happen, if they don't see the 'correct' KV, you will end up with lost updates.
>
> In theory the 'read memstore first' and 'order duplicate TS KVs' patches should resolve this. Lost updates reallllllly suck though. I'd probably recommend the conservative course, because I already went thru this and it sucks. If you decide that you are willing to risk it, I might recommend this particular test case:
>
> - increment some data at TS=X
> - snapshot at TS=X
> - increment some data at TS=X, now you have 2 * KV, TS=X
> - flush to hfile
> - increment at TS=X, ensure you dont lose any updates
> - snapshot/flush with TS=X in kvset->snapshot->hfile
> - compact the 2 hfiles both with TS=X in them
> - do read and make sure the value is what you expect.
>
> By using the manual environment edge you can control the currentTimeMillis() returned inside HRegion and down.
>
> This covers the worst case scenario I think, since normally one would get increments and you shouldn't get TS=X * 2 in a single HFile.
Yeah, we should now be handling these duplicate version things correctly. I guess you're saying you don't necessarily trust it.
I agree that a good test would be best. I don't have time to write that now unfortunately.
What's there now seems kind of hacky... if it finds something in snapshot, it adds 1 to the timestamp and puts that in memstore. but looking at your example above, wouldn't what's the existing behavior break?
When you increment at TS=X and there is TS=X in the snapshot, it then inserts it into MemStore as TS=X+1. Then if you insert to MemStore again at TS=X. It won't be in snapshot (it's been flushed), so then when you look for the latest value / go to delete old ones, you do memstore.tailSet(TS=X). Right? I could be missing something.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 495
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line495>
> >
> > yeah you cant compare against memstoreTS because if you have this in here you wont be able to ever increment values that were inserted into the future. you'd just leave them there and continually see it in the 'get' part and then in this code bit leave it in place and create a new KV that is masked by the future KV.
> >
> > It won't be possible for that insert to be part of an uncommitted change because of the rowlock however. So no atomic-rules will have been broken.
>
> Jonathan Gray wrote:
> i'm not sure i follow. am i doing it wrong? this should be exactly the same as what's there.
>
> also, we are breaking the atomic-rules across the Increment. Each column is not broken but across them it is (for reads not writes).
>
> It seems like we could use RWCC though for increments. I think it's fine that if you're using increment you can never write data into it w/ another API (or really, with manual timestamps).
>
> Ryan Rawson wrote:
> there is no easy way to include RWCC right now, because you have to be careful about 'committing' the new values before removing the old ones. This is a bit tricky because normally the RWCC 'commit' happens at the HRegion level, and right now we are inside memstore/store. Hopefully people won't need atomic reads of multi incremented values. If one is doing counters this would be the case. Javadoc should definitely yell about this.
Added more comments into the new methods javadoc.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 466
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line466>
> >
> > im not sure i like the name upsert, it is too rdbms-y for me.
> >
> > I need to poke more at this, but i prever the matchingRow() call, it encapsulates the getRowOffset junk, which leaks wayyy too much all over the place.
> >
> >
>
> Jonathan Gray wrote:
> Sure, could use those calls. Not even sure why I changed this, wrote that part of this patch a few weeks ago.
>
> And it's an "update if it exists, insert if not" operation which I think of as an upsert operation. Open to whatever tho.
Okay, changed those to matchingRow(), etc...
- Jonathan
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/#review1641
-----------------------------------------------------------
On 2010-10-24 19:29:07, Jonathan Gray wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1088/
> -----------------------------------------------------------
>
> (Updated 2010-10-24 19:29:07)
>
>
> Review request for hbase, stack and khemani.
>
>
> Summary
> -------
>
> Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
>
> The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
>
> The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
>
>
> This addresses bug HBASE-2946.
> http://issues.apache.org/jira/browse/HBASE-2946
>
>
> Diffs
> -----
>
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
> trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026930
> trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026930
>
> Diff: http://review.cloudera.org/r/1088/diff
>
>
> Testing
> -------
>
> Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
>
>
> Thanks,
>
> Jonathan
>
>
Re: Review Request: Increment multiple columns in a row at once
Posted by Jonathan Gray <jg...@apache.org>.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java, line 195
> > <http://review.cloudera.org/r/1088/diff/2/?file=15905#file15905line195>
> >
> > adding trailing spaces
> >
that's my patch removing trailing spaces
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java, line 201
> > <http://review.cloudera.org/r/1088/diff/2/?file=15905#file15905line201>
> >
> > adding more trailing spaces, your ide should have a feature to strip these
same here... i'm on the right :)
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 495
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line495>
> >
> > yeah you cant compare against memstoreTS because if you have this in here you wont be able to ever increment values that were inserted into the future. you'd just leave them there and continually see it in the 'get' part and then in this code bit leave it in place and create a new KV that is masked by the future KV.
> >
> > It won't be possible for that insert to be part of an uncommitted change because of the rowlock however. So no atomic-rules will have been broken.
i'm not sure i follow. am i doing it wrong? this should be exactly the same as what's there.
also, we are breaking the atomic-rules across the Increment. Each column is not broken but across them it is (for reads not writes).
It seems like we could use RWCC though for increments. I think it's fine that if you're using increment you can never write data into it w/ another API (or really, with manual timestamps).
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 377
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line377>
> >
> > I'm not sure how this code is optional for your new 'upsert', here are some use cases that I found painful:
> >
> > - when the KV is in snapshot we can create new KVs in memstore with the same TS. This means you have a dup and before we had this new 'dup' code it ruined counts badly.
> > - the Math.max() bit it to ensure the new KV isnt being created in the past a bit and accidently duplicating a timestamp inside the snapshot.
what do you mean by optional? there shouldn't be any real difference. this code is basically the exact same code that was there but now pulled into a method that can be reused.
> On 2010-10-24 20:05:55, Ryan Rawson wrote:
> > trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java, line 466
> > <http://review.cloudera.org/r/1088/diff/2/?file=15909#file15909line466>
> >
> > im not sure i like the name upsert, it is too rdbms-y for me.
> >
> > I need to poke more at this, but i prever the matchingRow() call, it encapsulates the getRowOffset junk, which leaks wayyy too much all over the place.
> >
> >
Sure, could use those calls. Not even sure why I changed this, wrote that part of this patch a few weeks ago.
And it's an "update if it exists, insert if not" operation which I think of as an upsert operation. Open to whatever tho.
- Jonathan
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/#review1641
-----------------------------------------------------------
On 2010-10-24 19:29:07, Jonathan Gray wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1088/
> -----------------------------------------------------------
>
> (Updated 2010-10-24 19:29:07)
>
>
> Review request for hbase, stack and khemani.
>
>
> Summary
> -------
>
> Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
>
> The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
>
> The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
>
>
> This addresses bug HBASE-2946.
> http://issues.apache.org/jira/browse/HBASE-2946
>
>
> Diffs
> -----
>
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
> trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026930
> trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026930
>
> Diff: http://review.cloudera.org/r/1088/diff
>
>
> Testing
> -------
>
> Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
>
>
> Thanks,
>
> Jonathan
>
>
Re: Review Request: Increment multiple columns in a row at once
Posted by Ryan Rawson <ry...@gmail.com>.
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1088/#review1641
-----------------------------------------------------------
trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java
<http://review.cloudera.org/r/1088/#comment5507>
adding trailing spaces
trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java
<http://review.cloudera.org/r/1088/#comment5508>
adding more trailing spaces, your ide should have a feature to strip these
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
<http://review.cloudera.org/r/1088/#comment5511>
I'm not sure how this code is optional for your new 'upsert', here are some use cases that I found painful:
- when the KV is in snapshot we can create new KVs in memstore with the same TS. This means you have a dup and before we had this new 'dup' code it ruined counts badly.
- the Math.max() bit it to ensure the new KV isnt being created in the past a bit and accidently duplicating a timestamp inside the snapshot.
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
<http://review.cloudera.org/r/1088/#comment5509>
im not sure i like the name upsert, it is too rdbms-y for me.
I need to poke more at this, but i prever the matchingRow() call, it encapsulates the getRowOffset junk, which leaks wayyy too much all over the place.
trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
<http://review.cloudera.org/r/1088/#comment5510>
yeah you cant compare against memstoreTS because if you have this in here you wont be able to ever increment values that were inserted into the future. you'd just leave them there and continually see it in the 'get' part and then in this code bit leave it in place and create a new KV that is masked by the future KV.
It won't be possible for that insert to be part of an uncommitted change because of the rowlock however. So no atomic-rules will have been broken.
- Ryan
On 2010-10-24 19:29:07, Jonathan Gray wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1088/
> -----------------------------------------------------------
>
> (Updated 2010-10-24 19:29:07)
>
>
> Review request for hbase, stack and khemani.
>
>
> Summary
> -------
>
> Adds a new Increment class that allows multiple columns (each w/ own increment amount) in a single row being incremented in one call.
>
> The big wins here are being able to do multiple columns in a row in a single RPC and having it be appended/synced to the WAL in a single call.
>
> The current trade-off is that you lose atomicity to readers (ie. this does not currently use RWCC). Eventually it could but for the current use case I am building this for, it's okay like this.
>
>
> This addresses bug HBASE-2946.
> http://issues.apache.org/jira/browse/HBASE-2946
>
>
> Diffs
> -----
>
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/HTableInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/client/Increment.java PRE-CREATION
> trunk/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java 1026930
> trunk/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java 1026930
> trunk/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 1026930
>
> Diff: http://review.cloudera.org/r/1088/diff
>
>
> Testing
> -------
>
> Added TestFromClientSide.testIncrement() which adds some client-side tests of Increment (and mixing w/ original icv call). That passes and most the way through a test suite run.
>
>
> Thanks,
>
> Jonathan
>
>