[SOLR-14251] Shard Split on HDFS

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 8.4
• Component/s: hdfs
• Assignee: Unassigned
• Reporter: Johannes Brucher
• Created: 10/Feb/20 10:42
• Updated: 28/Oct/22 19:16
• Resolved: 28/Oct/22 13:52

Description

Shard Split on HDFS Index will evaluate local disc space instead of HDFS space

When performing a shard split on an index that is stored on HDFS the SplitShardCmd however evaluates the free disc space on the local file system of the server where Solr is installed.

SplitShardCmd assumes that its main phase (when the Lucene index is being split) always executes on the local file system of the shard leader; and indeed the ShardSplitCmd.checkDiskSpace() checks the local file system's free disk space - even though the actual data is written to the HDFS Directory so it (almost) doesn't affect the local FS (except for core.properties file).

See also: https://lucene.472066.n3.nabble.com/HDFS-Shard-Split-td4449920.html

My setup to reproduce the issue:

• Solr deployed on Openshift with local disc of about 5GB
• HDFS configuration based on solrconfig.xml with

<directoryFactory name="DirectoryFactory" class="solr.HdfsDirectoryFactory">
    <str name="solr.hdfs.home">hdfs://path/to/index/</str>
...

• Split command:

.../admin/collections?action=SPLITSHARD&collection=collection1&shard=shard1&async=1234

• Response:

{
  "responseHeader":{"status":0,"QTime":32},
  "Operation splitshard caused exception:":"org.apache.solr.common.SolrException:org.apache.solr.common.SolrException: not enough free disk space to perform index split on node <solr instance>:8983_solr, required: 294.64909074269235, available: 5.4632568359375",
  "exception":{
    "msg":"not enough free disk space to perform index split on node <solr instance>:8983_solr, required: 294.64909074269235, available: 5.4632568359375",
    "rspCode":500},
  "status":{"state":"failed","msg":"found [1234] in failed tasks"}
}

 

 

Issue Links

• is fixed by: SOLR-16353 SplitShardCmd.checkDiskSpace can fail for transient core
• links to: GitHub Pull Request #1108
• links to: GitHub Pull Request #2137