This is the documentation for Cloudera Search 1.3.0 for CDH 4.
Documentation for other versions is available at Cloudera Documentation.

Known Issues and Limitations in the Current Release

The current release includes the following known limitations:

— Enabling blockcache writing may result in unusable indexes

It is possible to create indexes with solr.hdfs.blockcache.write.enabled set to true. Such indexes may appear corrupt to readers, and reading these indexes may irrecoverably corrupt indexes. Blockcache writing is disabled by default.

Severity: Medium

Workaround: Do not enable blockcache writing.

— Solr fails to start when Trusted Realms are added for Solr into Cloudera Manager

Cloudera Manager generates name rules with spaces as a result of entries in the Trusted Realms, which do not work with Solr. This causes Solr to not start.

Severity: Medium

Workaround: Do not use the Trusted Realm field for Solr in Cloudera Manager. To write your own name rule mapping, add an environment variable SOLR_AUTHENTICATION_KERBEROS_NAME_RULES with the mapping. See the Cloudera Manager Security Guide for more information.

— Lily HBase batch indexer jobs fail to launch

A symptom of this issue is an exception similar to the following:
Exception in thread "main" java.lang.IllegalAccessError: class com.google.protobuf.ZeroCopyLiteralByteString cannot access its superclass com.google.protobuf.LiteralByteString
	at java.lang. ClassLoader.defineClass1(Native Method)
	at java.lang. ClassLoader.defineClass( ClassLoader.java:792)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang. ClassLoader.loadClass( ClassLoader.java:424)
	at java.lang. ClassLoader.loadClass( ClassLoader.java:357)
	at org.apache.hadoop.hbase.protobuf.ProtobufUtil.toScan(ProtobufUtil.java:818)
	at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.convertScanToString(TableMapReduceUtil.java:433)
	at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.initTableMapperJob(TableMapReduceUtil.java:186)
	at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.initTableMapperJob(TableMapReduceUtil.java:147)
	at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.initTableMapperJob(TableMapReduceUtil.java:270)
	at org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil.initTableMapperJob(TableMapReduceUtil.java:100)
	at com.ngdata.hbaseindexer.mr.HBaseMapReduceIndexerTool.run(HBaseMapReduceIndexerTool.java:124)
	at com.ngdata.hbaseindexer.mr.HBaseMapReduceIndexerTool.run(HBaseMapReduceIndexerTool.java:64)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at com.ngdata.hbaseindexer.mr.HBaseMapReduceIndexerTool.main(HBaseMapReduceIndexerTool.java:51)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.hadoop.util.RunJar.main(RunJar.java:212)
This is because of an optimization introduced in HBASE-9867 that inadvertently introduced a classloader dependency. In order to satisfy the new classloader requirements, hbase-protocol.jar must be included in Hadoop's classpath. This can be resolved on a per-job launch basis by including it in the HADOOP_CLASSPATH environment variable when you submit the job.

Severity: High

Workaround: Run the following command before issuing Lily HBase MapReduce jobs. Replace the .jar file names and filepaths as appropriate.
$ export HADOOP_CLASSPATH=</path/to/hbase-protocol>.jar; hadoop jar <MyJob>.jar <MyJobMainClass>

— Users may receive limited error messages on requests in Sentry-protected environment.

Users submit requests which are received by a node. The node that receives the request may be different from the node with the relevant information. In such a case, Solr forwards the request to the appropriate node. Once the correct node receives the request, Sentry may deny access.

Because the request was forwarded, available information may be limited. In such a case, the user's client display the error message Server returned HTTP response code: 401 for URL: followed by the Solr machine reporting the error.

Severity: Low

Workaround: For complete error information, review the contents of the Solr logs on the machine reporting the error.

— Users with insufficient Solr permissions may receive a "Page Loading" message from the Solr Web Admin UI

Users who are not authorized to use the Solr Admin UI are not given page explaining that access is denied, and instead receive a web page that never finishes loading.

Severity: Low

Workaround: None

— Mapper-only HBase batch indexer fails if configured to use security.

Attempts to complete an HBase batch indexing job fail when Kerberos authentication is enabled and reducers is set to 0.

Workaround: Either disable Kerberos authentication or use one or more reducers.

— Using MapReduceIndexerTool or HBaseMapReduceIndexerTool multiple times may produce duplicate entries in a collection.

Repeatedly running the MapReduceIndexerTool on the same set of input files can result in duplicate entries in the Solr collection. This occurs because the tool can only insert documents and cannot update or delete existing Solr documents.

Severity: Medium

Workaround: To avoid this issue, use HBaseMapReduceIndexerTool with zero reducers. This must be done without Kerberos.

— Deleting collections may fail if nodes are unavailable.

It is possible to delete a collection when nodes that host some of the collection are unavailable. After such a deletion, if the previously unavailable nodes are brought back online, the deleted collection may be restored.

Severity: Low

Workaround: Ensure all nodes are online before deleting collections.

— Lily HBase Indexer is slow to index new data after restart.

After restarting the Lily HBase Indexer, you can add data to one of the HBase tables. There may be a delay of a few minutes before this newly added data appears in Solr. This delay only occurs with a first HBase addition after a restart. Similar subsequent additions are not subject to this delay.

Severity: Low

Workaround: None

— Some configurations for Lily HBase Indexers cannot be modified after initial creation.

Newly created Lily HBase Indexers define their configuration using the properties in /etc/hbase-solr/conf/hbase-indexer-site.xml. Therefore, if the properties in the hbase-indexer-site.xml file are incorrectly defined, new indexers do not work properly. Even after correcting the contents of hbase-indexer-site.xml and restarting the indexer service, old, incorrect content persists. This continues to create non-functioning indexers.

Severity: Medium

Workaround:
  Warning: This workaround involves completing destructive operations that delete all of your other Lily HBase Indexers.
To resolve this issue:
  1. Connect to each machine running the Lily HBase Indexer service using the NGdata and stop the indexer:
    service hbase-solr-indexer stop
      Note: You may need to stop the service on multiple machines.
  2. For each indexer machine, modify the /etc/hbase-solr/conf/hbase-indexer-site.xml file to include valid settings.
  3. Connect to the ZooKeeper machine, invoke the ZooKeeper CLI, and remove all contents of the /ngdata chroot:
    $ /usr/lib/zookeeper/bin/zkCli.sh
    [zk: localhost:2181( CONNECTED) 0] rmr /ngdata
  4. Connect to each indexer machine and restart the indexer service.
    service hbase-solr-indexer start

After restarting the client services, ZooKeeper is updated with the correct information stored on the updated clients.

— Saving search results is not supported in this release.

This version of Cloudera Search does not support the ability to save search results.

Severity: Low

Workaround: None

— HDFS Federation is not supported in this release.

This version of Cloudera Search does not support HDFS Federation.

Severity: Low

Workaround: None

— Block Cache Metrics are not supported in this release.

This version of Cloudera Search does not support block cache metrics.

Severity: Low

Workaround: None

— Shard splitting support is experimental.

Shard splitting was added with the recent release of Solr 4.4. Cloudera anticipates shard splitting to function as expected with Cloudera Search, but this interaction has not been thoroughly tested. Therefore, Cloudera cannot guarantee issues will not arise when shard splitting is used with Search.

Severity: Low

Workaround: Use shard splitting for test and development purposes, but be aware of the risks of using shard splitting in production environments. To avoid using shard splitting, use the source data to create a new index with a new sharding count by re-indexing the data to a new collection. You can enable this using the MapReduceIndexerTool.

— User with update access to the administrative collection can elevate the access.

Users are granted access to collections. Access to several collections can be simplified by aliasing a set of collections. Creating an alias requires update access to the administrative collection. Any user with update access to the administrative collection is granted query access to all collections in the resulting alias. This is true even if the user with update access to the administrative collection otherwise would be unable to query the other collections that have been aliased.

Severity: Medium

Workaround: None. Mitigate the risk by limiting the users with update access to the administrative collection.