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https://issues.apache.org/jira/browse/HUDI-3066?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17462954#comment-17462954
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Manoj Govindassamy edited comment on HUDI-3066 at 12/21/21, 3:16 AM:
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[~h7kanna]
1. After migrating the table to 0.10 with metadata turned on, did you add more
commits to it before the performance comparison?
2. From the log I can see 437 metadata log files and the overall read took
~22.9 seconds. That is, ~52 millis for each S3 log file, which is ok when
accessing files over S3. But, 437 log files for metadata table is definitely on
the higher side. Metadata table internal automatic compaction kicks for every
10 commits. This doesn't look like happened from the messages you shared.
Metadata table compaction could be blocked because of any pending table service
operations (like clustering) on the data table. Can you please post the data
table .hoodie listing? Something like below.
For table backed by DFS
{noformat}
$ ls -lrth -a <table_base_path>.hoodie/ {noformat}
For table backed by S3
{noformat}
$ aws s3 ls s3://<table_base_path>/.hoodie/{noformat}
Once compaction in the metadata table is completed successfully, there should
be far minimal log file to read for the listing.
was (Author: manojg):
[~h7kanna]
1. After migrating the table to 0.10 with metadata turned on, did you add more
commits to it before the performance comparison?
2. From the log I can see 437 metadata log files and the overall read took
~22.9 seconds. That is, ~52 millis for each S3 log file, which is ok when
accessing files over S3. But, 437 log files for metadata table is definitely on
the higher side. Metadata table internal automatic compaction kicks for every
10 commits. This doesn't look like happened from the messages you shared.
Metadata table compaction could be blocked because of any pending table service
operations (like clustering) on the data table. Can you please post the data
table `.hoodie` listing?
$ `ls -lrt -a <table_base_path>.hoodie/`
Once compaction in the metadata table is completed successfully, there should
be far minimal log file to read for the listing.
> Very slow file listing after enabling metadata for existing tables in 0.10.0
> release
> ------------------------------------------------------------------------------------
>
> Key: HUDI-3066
> URL: https://issues.apache.org/jira/browse/HUDI-3066
> Project: Apache Hudi
> Issue Type: Bug
> Affects Versions: 0.10.0
> Environment: EMR 6.4.0
> Hudi version : 0.10.0
> Reporter: Harsha Teja Kanna
> Assignee: Manoj Govindassamy
> Priority: Major
> Labels: performance, pull-request-available
> Attachments: Screen Shot 2021-12-18 at 6.16.29 PM.png
>
>
> After 'metadata table' is enabled, File listing takes long time.
> If metadata is enabled on Reader side(as shown below), it is taking even more
> time per file listing task
> {code:java}
> import org.apache.hudi.DataSourceReadOptions
> import org.apache.hudi.common.config.HoodieMetadataConfig
> val hadoopConf = spark.conf
> hadoopConf.set(HoodieMetadataConfig.ENABLE.key(), "true")
> val basePath = "s3a://datalake-hudi"
> val sessions = spark
> .read
> .format("org.apache.hudi")
> .option(DataSourceReadOptions.QUERY_TYPE.key(),
> DataSourceReadOptions.QUERY_TYPE_SNAPSHOT_OPT_VAL)
> .option(DataSourceReadOptions.READ_PATHS.key(),
> s"${basePath}/sessions_by_entrydate/entrydate=2021/*/*/*")
> .load()
> sessions.createOrReplaceTempView("sessions") {code}
> Existing tables (COW) have inline clustering on and have many replace commits.
> Logs seem to suggest the delay is in view.AbstractTableFileSystemView
> resetFileGroupsReplaced function or metadata.HoodieBackedTableMetadata
> Also many log messages in AbstractHoodieLogRecordReader
>
> 2021-12-18 23:17:54,056 INFO view.AbstractTableFileSystemView: Took 4118 ms
> to read 136 instants, 9731 replaced file groups
> 2021-12-18 23:37:46,086 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,090 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.76_0-20-515
> at instant 20211217035105329
> 2021-12-18 23:37:46,090 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,094 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.121_0-57-663',
> fileLen=0}
> 2021-12-18 23:37:46,095 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.20_0-35-613',
> fileLen=0}
> 2021-12-18 23:37:46,095 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,096 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.62_0-34-377
> at instant 20211217022049877
> 2021-12-18 23:37:46,096 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,105 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.86_0-20-362',
> fileLen=0}
> 2021-12-18 23:37:46,109 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.121_0-57-663',
> fileLen=0}
> 2021-12-18 23:37:46,109 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,110 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.77_0-35-590',
> fileLen=0}
> 2021-12-18 23:37:46,112 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.20_0-35-613
> at instant 20211216183448389
> 2021-12-18 23:37:46,112 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,118 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.63_0-56-519',
> fileLen=0}
> 2021-12-18 23:37:46,122 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.86_0-20-362',
> fileLen=0}
> 2021-12-18 23:37:46,122 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,123 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.121_0-57-663
> at instant 20211217090337935
> 2021-12-18 23:37:46,123 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,127 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.77_0-35-590',
> fileLen=0}
> 2021-12-18 23:37:46,127 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,141 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.21_0-56-795',
> fileLen=0}
> 2021-12-18 23:37:46,143 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.63_0-56-519',
> fileLen=0}
> 2021-12-18 23:37:46,143 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,144 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.86_0-20-362
> at instant 20211217045206861
> 2021-12-18 23:37:46,144 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,145 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.77_0-35-590
> at instant 20211217035058289
> 2021-12-18 23:37:46,145 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,162 INFO log.AbstractHoodieLogRecordReader: Scanning log
> file
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.21_0-56-795',
> fileLen=0}
> 2021-12-18 23:37:46,162 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.63_0-56-519
> at instant 20211217022306173
> 2021-12-18 23:37:46,162 INFO s3a.S3AInputStream: Switching to Random IO seek
> policy
> 2021-12-18 23:37:46,162 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge 1
> 2021-12-18 23:37:46,170 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.87_0-35-433',
> fileLen=0}
> 2021-12-18 23:37:46,171 INFO log.HoodieLogFormatReader: Moving to the next
> reader for logfile
> HoodieLogFile\{pathStr='s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.78_0-56-705',
> fileLen=0}
> 2021-12-18 23:37:46,178 INFO log.AbstractHoodieLogRecordReader: Reading a
> data block from file
> s3a://datalake-hudi/sessions/.hoodie/metadata/files/.files-0000_20211216144130775001.log.21_0-56-795
> at instant 20211216184106961
> 2021-12-18 23:37:46,178 INFO log.AbstractHoodieLogRecordReader: Number of
> remaining logblocks to merge
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner: Number of log
> files scanned => 437
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner:
> MaxMemoryInBytes allowed for compaction => 1073741824
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner: Number of
> entries in MemoryBasedMap in ExternalSpillableMap => 165
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner: Total size in
> bytes of MemoryBasedMap in ExternalSpillableMap => 259380
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner: Number of
> entries in BitCaskDiskMap in ExternalSpillableMap => 0
> 2021-12-18 23:38:35,380 INFO log.HoodieMergedLogRecordScanner: Size of file
> spilled to disk => 0
> 2021-12-18 23:38:35,380 INFO metadata.HoodieBackedTableMetadata: Opened 437
> metadata log files (dataset instant=20211218233649435, metadata
> instant=20211218233649435) in 22935 ms
> 2021-12-18 23:38:37,193 INFO metadata.HoodieBackedTableMetadata: Opened 437
> metadata log files (dataset instant=20211218233649435, metadata
> instant=20211218233649435) in 22802 ms
> Sample file listing tasks
> !Screen Shot 2021-12-18 at 6.16.29 PM.png!
>
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