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https://issues.apache.org/jira/browse/HBASE-4532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13131191#comment-13131191
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[email protected] commented on HBASE-4532:
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bq. On 2011-10-19 19:02:46, Kannan Muthukkaruppan wrote:
bq. > src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java, line
1058
bq. > <https://reviews.apache.org/r/2393/diff/2/?file=50558#file50558line1058>
bq. >
bq. > not clear where you are using this "-1" state
Even if there is no delete family bloom filter, the Store file will still count
how many delete family key values and append this information into HFile's File
info.
So when reading the file, we will know how many delete family kvs.
However, if there is no this delete family field in the file info,
deleteFamilyCnt shall be set to -1. So the function
passesDeleteFamilyBloomFilter won't take this into account.
bq. On 2011-10-19 19:02:46, Kannan Muthukkaruppan wrote:
bq. > src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java, line
1217
bq. > <https://reviews.apache.org/r/2393/diff/2/?file=50558#file50558line1217>
bq. >
bq. > To make sure I understand this...
bq. >
bq. > for "HFileV1" case or for "HFileV2 + but without this fix", I am
guessing deleteFamilyCnt will be equal to -1, and the fact that it doesn't have
a bloomFilter will cause it to return true. That look's fine. Just not obvious.
Yes:) If there is a deleteFamilyCnt and the deleteFamilyCnt is 0, then there is
no need to check Bloom filter and return false for function
passesDeleteFamilyBloomFilter(). It means there is no need to seek this store
file for delete family with the row.
if the deleteFamilyCnt is not initialized properly for some reason, which is
set to -1, then it needs to check the delete family bloom filter.
So there is no delete family bloom filter, it will return true. It means it is
possible that there is a delete family for this row.
bq. On 2011-10-19 19:02:46, Kannan Muthukkaruppan wrote:
bq. >
src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java, line
238
bq. > <https://reviews.apache.org/r/2393/diff/2/?file=50559#file50559line238>
bq. >
bq. > In case there is a deleteFamily kv, there are two sub-cases here...
bq. >
bq. > a) we have ROWCOL bloom (in which case there is no
DeleteFamilyBloomFilter) and we want to use the ROWCOL bloom filter itself.
bq. >
bq. > b) we have a DeleteFamilyBloomFilter.
bq. >
bq. > I don't see us taking advantage of (a) like we used to earlier.
Isn't this a regression for the ROWCOL bloom case? And if so, TestBlocksRead
should have caught it, no?
1) Yes, it should the ROWCOL Bloom filter. It can also help to warm up row col
bloom filter in the cache OR get benefit from block cache.
I will update the code.
2) There is no regression for the ROWCOL bloom case. It is because we only
count for data block seek number.
No matter which bloom filter (delete family or row col), it will return the
same result. So it won't affect the decision whether to seek to the store file
file or not.
Please correct me if I am wrong :)
bq. On 2011-10-19 19:02:46, Kannan Muthukkaruppan wrote:
bq. > src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java,
line 111
bq. > <https://reviews.apache.org/r/2393/diff/2/?file=50560#file50560line111>
bq. >
bq. > isSeekToEmptyColumn and useBloom should be separate flags I think.
bq. >
bq. > For example, if the CF had ROWCOL bloom, and the query for looking
for "row/0-length column", then with this change, we won't use the ROWCOL bloom
filter even when it exists.
bq. >
bq. > Isn't it the case that we want to avoid using only the
deleteFamilyBloom filter when isSeekToEmptyColumn is true?
Agree:) I will update the code to pass the scan query matcher to each store
file scanner. Also this will help us for further optimization.
When the store file scanner has more information about the matcher's status, it
may help to avoid more unnecessarily seeks.
- Liyin
-----------------------------------------------------------
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-----------------------------------------------------------
On 2011-10-20 00:08:14, Liyin Tang wrote:
bq.
bq. -----------------------------------------------------------
bq. This is an automatically generated e-mail. To reply, visit:
bq. https://reviews.apache.org/r/2393/
bq. -----------------------------------------------------------
bq.
bq. (Updated 2011-10-20 00:08:14)
bq.
bq.
bq. Review request for hbase, Dhruba Borthakur, Michael Stack, Mikhail Bautin,
Pritam Damania, Prakash Khemani, Amitanand Aiyer, Kannan Muthukkaruppan, Jerry
Chen, Liyin Tang, Karthik Ranganathan, and Nicolas Spiegelberg.
bq.
bq.
bq. Summary
bq. -------
bq.
bq. HBASE-4469 avoids the top row seek operation if row-col bloom filter is
enabled.
bq. This jira tries to avoid top row seek for all the cases by creating a
dedicated bloom filter only for delete family
bq.
bq. The only subtle use case is when we are interested in the top row with
empty column.
bq.
bq. For example,
bq. we are interested in row1/cf1:/1/put.
bq. So we seek to the top row: row1/cf1:/MAX_TS/MAXIMUM. And the delete family
bloom filter will say there is NO delete family.
bq. Then it will avoid the top row seek and return a fake kv, which is the
last kv for this row (createLastOnRowCol).
bq. In this way, we have already missed the real kv we are interested in.
bq.
bq. The solution for the above problem is to disable this optimization if we
are trying to GET/SCAN a row with empty column.
bq.
bq. This patch is rebased on 0.89-fb. But it should be the same for
apache-trunk as well. I will submit the patch for apache-trunk later.
bq.
bq.
bq. This addresses bug HBASE-4532.
bq. https://issues.apache.org/jira/browse/HBASE-4532
bq.
bq.
bq. Diffs
bq. -----
bq.
bq. src/main/java/org/apache/hadoop/hbase/KeyValue.java 93538bb
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/BlockType.java 9a79a74
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFile.java 5d9b518
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFilePrettyPrinter.java
6cf7cce
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderV1.java
1f78dd4
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderV2.java
3c34f86
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterV1.java
2e1d23a
bq. src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterV2.java
c4b60e9
bq. src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java
92070b3
bq. src/main/java/org/apache/hadoop/hbase/regionserver/StoreFile.java
e4dfc2e
bq. src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java
ebb360c
bq. src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java
8814812
bq. src/main/java/org/apache/hadoop/hbase/util/BloomFilterFactory.java
fb4f2df
bq. src/test/java/org/apache/hadoop/hbase/regionserver/TestBlocksRead.java
b8bcc65
bq.
src/test/java/org/apache/hadoop/hbase/regionserver/TestCompoundBloomFilter.java
48e9163
bq. src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreFile.java
0eca9b8
bq.
bq. Diff: https://reviews.apache.org/r/2393/diff
bq.
bq.
bq. Testing
bq. -------
bq.
bq. Running all the unit tests now
bq.
bq.
bq. Thanks,
bq.
bq. Liyin
bq.
bq.
> Avoid top row seek by dedicated bloom filter for delete family bloom filter
> ---------------------------------------------------------------------------
>
> Key: HBASE-4532
> URL: https://issues.apache.org/jira/browse/HBASE-4532
> Project: HBase
> Issue Type: Improvement
> Reporter: Liyin Tang
> Assignee: Liyin Tang
> Attachments: D27.1.patch, D27.1.patch
>
>
> HBASE-4469 avoids the top row seek operation if row-col bloom filter is
> enabled.
> This jira tries to avoid top row seek for all the cases by creating a
> dedicated bloom filter only for delete family
> The only subtle use case is when we are interested in the top row with empty
> column.
> For example,
> we are interested in row1/cf1:/1/put.
> So we seek to the top row: row1/cf1:/MAX_TS/MAXIMUM. And the delete family
> bloom filter will say there is NO delete family.
> Then it will avoid the top row seek and return a fake kv, which is the last
> kv for this row (createLastOnRowCol).
> In this way, we have already missed the real kv we are interested in.
> The solution for the above problem is to disable this optimization if we are
> trying to GET/SCAN a row with empty column.
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