LATEST VERSION: 2.2.1 - CHANGELOG
Pivotal Greenplum GPText v2.2.1

PivotalĀ® GPText 2.1 Release Notes

This document contains release information for Pivotal GPText 2.1.

Published: June 2017

About Pivotal GPText

Pivotal GPText joins the Greenplum Database massively parallel-processing database server with Apache SolrCloud enterprise search and the Apache MADlib Analytics Library to provide large-scale analytics processing and business decision support. GPText includes free text search as well as support for text analysis.

GPText includes the following features:

  • The GPText database schema provides in-database access to Apache Solr indexing and searching
  • Custom tokenizers for international text and social media text
  • A Universal Query Processor that accepts queries with mixed syntax from supported Solr query processors
  • Faceted search results
  • Term highlighting in results
  • Greater emphasis on high availability

The GPText management utility suite includes command-line utilities to perform the following tasks:

  • Start, stop, and monitor ZooKeeper and GPText nodes
  • Configure GPText nodes and indexes
  • Add and delete replicas for index shards
  • Back up and restore GPText indexes
  • Recover a GPText node
  • Expand the GPText cluster by adding GPText nodes

Prerequisites

Installing GPText also installs Apache Solr Cloud and, optionally, Apache ZooKeeper.

Following are GPText installation prerequisites.

  • Install and configure your Greenplum Database system, version 4.3.6 or higher. See the Pivotal Greenplum Database Installation Guide at https://gpdb.docs.pivotal.io.
  • GPText runs on Red Hat Enterprise Linux 5.x or 6.x.
  • GPText cannot be installed onto a shared NFS mount.
  • Install Oracle JRE 1.8.x and add its bin directory to the PATH on all hosts in the cluster.
  • Ensure that nc (netcat) is installed on all Greenplum cluster hosts (sudo yum install nc).
  • Installing lsof on all cluster hosts is recommended (sudo yum install lsof).
  • GPText nodes can be installed on the Greenplum Database cluster hosts alongside the Greenplum segments or on additional, non-database hosts accessible on the Greenplum cluster network. All hosts participating in the GPText system must have the same operating system and configuration and have passwordless-ssh access for the gpadmin user. See the Pivotal Greenplum Database Installation Guide for instructions to configure hosts.
  • If you plan to place GPText nodes on the Greenplum Database segment hosts, ensure that you reserve memory for GPText use when you configure Greenplum Database. To determine the memory to set aside for GPText, multiply the number of GPText nodes to create on each Greenplum segment host by the JVM maximum size. Subtract this memory from the physical RAM when calculating the value for the Greenplum Database gp_vmem_protect_limit server configuration parameter. See the Greenplum Database server configuration parameter gp_vmem_protect_limit in the Greenplum Database Reference Guide for recommended memory calculation formulas or visit the GPDB Virtual Memory Calculator web site.
  • Apache Solr requires a ZooKeeper cluster with at minimum three nodes (five nodes recommended). You can install a “binding” ZooKeeper cluster with GPText on the Greenplum cluster hosts, or you can use an existing ZooKeeper cluster. When deployed alongside Greenplum Database segments, ZooKeeper performance can be affected under heavy database load. For best performance, install a ZooKeeper cluster on separate hosts with network connectivity to the Greenplum network.

New Features and Enhancements in GPText 2.1

  • Previously, all ZooKeeper nodes running on the same host wrote messages to the same log file. Now each node writes to a log file in its own data directory.
  • GPText was unable to parse “-” and “_” characters in the ZOO_HOSTS configuration parameter in the gptext_install_config file. This is fixed.
  • The gptext-state management utility has a new -D (--details) option. The default format for the utility’s output is changed to display counts of indexes in the Green, Yellow, and Red states. With the -D option, the command includes the Green, Yellow, or Red status of each GPText index. The utility returns a non-zero status if any indexes are not in the Green state.
  • Optimizations and changes have been made to make starting up a GPText cluster with a large number of indexes more stable:
    • The default value of the replication_factor configuration parameter is changed from 3 to 2.
    • The gptext-start utility has a new --slow-start (-s) option that performs a “rolling-start,” starting up one index at a time. This option should be used when starting a GPText cluster that has a large number of indexes. If you have more than 50 indexes and omit this option, the utility prompts you to confirm that you want to perform a fast startup.
    • One GPText instance on each host in the cluster is assigned the overseer role to help reduce demand on ZooKeeper.
    • The coreLoadThreads in thesolr.xml configuration file is increased to 512.
    • The solr.jetty.threads.max parameter in the jetty.xml file for each Solr binary is increased to 30000.
  • Added support for indexing Greenplum Database partitioned tables.
    • A Boolean partitioned column is added to the results of the gptext.index_status() function.
    • The gptext-state -i <index_name> command includes a list of child partition indexes for partitioned tables in all databases.
    • A new gptext.partition_status() function lists child partition indexes in the current database.
  • GPText nodes are no longer required to run on Greenplum Database segment hosts. GPText nodes can be deployed on separate hosts with connectivity to the Greenplum network, and passwordless-ssh access for the gpadmin user between all Greenplum Database and GPText nodes. The GPText installer and the gptext-uninstall, gptext-expand, and gptext-recover management utilities are updated to accommodate this change.
  • Added a utility, gptext_migrator, to migrate a GPText system into a Greenplum Database cluster that has been upgraded to a new GPDB release. Migrating does not change the GPText version; it moves the current GPText system to a different Greenplum Database cluster. Migrating a GPText system from GPDB 4.3.x to GPDB 5.x is not currently supported.
  • The GPText 2.1 installer can upgrade a GPText 2.0 system to the new GPText release. If requested, the installer runs a new utility, gptext-upgrade, to upgrade the GPText system. The gptext-upgrade utility can also be run separately from the installer.

Known Issues

Following are known issues in GPText. Workarounds are provided when available.

Wildcards in GPText Search Options

Solr does not return all fields when the fl Solr search option contains a wildcard that matches field names. For example, given a table with columns contenta and contentb, specifying fl=contenta,contentb,(sum,1,1) correctly returns three fields. Specifying fl=cont*,sum(1,1) correctly returns contenta and contentb, but omits the pseudo-field sum(1,1).

Specifying a wildcard to match all fields (fl=*,sum(1,1)) also omits the pseudo-field.

Index Load Failure After Configuration File Error

If Solr fails to load an index because of a configuration file error, and then the index is dropped without first correcting the configuration file error, the index cannot be recreated until GPText is restarted. This can happen if you edit managed-schema or solrconfig.xml and introduce an XML syntax error or a typo in configuration values.

Workaround:

  1. When an index fails to load, check the Solr log to find the cause.
  2. If the cause is a configuration file error, such as invalid XML, use the gptext-config utility to edit the file and fix the error. Dropping the index without first correcting the error is not recommended.
  3. If you have dropped an index that failed to load without first correcting the cause of the failure, you must restart GPText before you can recreate the index. Run gptext-start -r to restart GPText.

Startup Failure with Large Numbers of Indexes

When there is a large number of Solr cores, Solr Cloud can fail to restart successfully, with error messages indicating failure to elect leaders for shards. This is a known Solr issue; see https://issues.apache.org/jira/browse/SOLR-5990 in the Apache Solr Jira for an example. Because of this issue, it is recommended to avoid designing GPText applications that create large numbers of indexes, shards, and replicas. The number of cores you can create before you observe this behavior is hardware dependent, so you should test to determine your system’s limits. You can create and successfully operate a larger numbers of indexes than can be restarted successfully later, so be sure to test restarting GPText to determine a practical limit.

Setting GPText Configuration Parameters Without First Setting custom_variable_classes

If the custom_variable_classes Greenplum Database server configuration parameter does not include the value “gptext”, attempting to set a GPText configuration parameter returns an error message, for example:

mydb-# set gptext.replication_factor = 4;
WARNING:  Please logon again to make GUC setting take effect. (GucValue.h:301)
WARNING:  Please logon again to make GUC setting take effect. (GucValue.h:301)
ERROR: unrecognized configuration parameter "gptext.replication_factor"

In GPText 2.0, in addition to the error message, the value of the configuration parameter persisted in ZooKeeper is zero, replacing the previous value of the parameter.

 mydb-# show gptext.replication_factor;
  gptext.replication_factor
 ----------------------------
  0

Beginning with GPText 2.1, the error message is still generated, however the value saved in ZooKeeper is the value specified in the set command, 4 in the preceding example.

To prevent the error message, before setting any GPText configuration parameters, use the gpconfig command-line utility to set the custom_variable_classes configuration parameter:

$ gpconfig -c custom_variable_classes -v 'gptext'