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https://issues.apache.org/jira/browse/HBASE-9270?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Rekha Joshi updated HBASE-9270:
-------------------------------
Attachment: HBASE-9270.1.patch
Patch has only forced return, as 0.94 has refined getTableInfoModtime(),
getTableDirModtime(), and overloaded getTableInfoPath() methods.
> [0.94] FSTableDescriptors caching is racy
> -----------------------------------------
>
> Key: HBASE-9270
> URL: https://issues.apache.org/jira/browse/HBASE-9270
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.94.11
> Reporter: Andrew Purtell
> Priority: Minor
> Attachments: HBASE-9270.1.patch
>
>
> An occasionally failing test in 0.92 branch that concurrently executes master
> operations on a single table found this problem in FSTableDescriptors:
> {code}
> diff --git src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> index e882621..b0042cd 100644
> --- src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> +++ src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
> @@ -221,8 +221,15 @@ public class FSTableDescriptors implements
> TableDescriptors {
> if
> (HConstants.HBASE_NON_USER_TABLE_DIRS.contains(htd.getNameAsString())) {
> throw new NotImplementedException();
> }
> - if (!this.fsreadonly) updateHTableDescriptor(this.fs, this.rootdir, htd);
> - long modtime = getTableInfoModtime(this.fs, this.rootdir,
> htd.getNameAsString());
> + if (fsreadonly) {
> + // Cannot cache here.
> + // We can't know if a modtime from the most recent file found in a
> + // directory listing at some arbitrary point in time still corresponds
> + // to the latest, nor that our htd is the latest.
> + return;
> + }
> + // Cache with the modtime of the descriptor we wrote
> + long modtime = updateHTableDescriptor(this.fs, this.rootdir,
> htd).getModificationTime();
> this.cache.put(htd.getNameAsString(), new
> TableDescriptorModtime(modtime, htd));
> }
> {code}
> After HBASE-7305 master operations are serialized by a write lock on the
> table.
> However, 0.94 has code with the same issue:
> {code}
> @Override
> public void add(HTableDescriptor htd) throws IOException {
> if (Bytes.equals(HConstants.ROOT_TABLE_NAME, htd.getName())) {
> throw new NotImplementedException();
> }
> if (Bytes.equals(HConstants.META_TABLE_NAME, htd.getName())) {
> throw new NotImplementedException();
> }
> if (HConstants.HBASE_NON_USER_TABLE_DIRS.contains(htd.getNameAsString()))
> {
> throw new NotImplementedException();
> }
> if (!this.fsreadonly) updateHTableDescriptor(this.fs, this.rootdir, htd);
> String tableName = htd.getNameAsString();
> long modtime = getTableInfoModtime(this.fs, this.rootdir, tableName);
> long dirmodtime = getTableDirModtime(this.fs, this.rootdir, tableName);
> this.cache.put(tableName, new TableDescriptorModtime(modtime, dirmodtime,
> htd));
> }
> {code}
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