Pivotal Greenplum® Command Center 6.3 Release Notes

Updated 2020-Sep-25

About This Release

This document contains release information about Pivotal Greenplum Command Center 6.3. Greenplum Command Center 6.3 provides management and monitoring functionality for Pivotal Greenplum Database 6.

This topic contains release notes for Greenplum Command Center 6.3.1 and Greenplum Command Center 6.3.0.

Supported Platforms

Greenplum Command Center 6.3 is compatible with the following platforms.

  • Pivotal Greenplum Database 6.x.
  • Red Hat Enterprise Linux 6.x1 and 7.x
  • CentOS 6.x1 and 7.x
  • SUSE Enterprise Linux 12
  • Ubuntu 18.04

See Pivotal Greenplum Command Center Supported Platforms for the most current compatibility information.

Enhancements and Changes in Greenplum Command Center 6.3.1

Changes

  • The GPCC web server configuration has been altered to reject unsafe DES ciphers.

Fixed Issues

  • [30954] - During security scans, some SSL ciphers were highlighted as “medium strength”. This issue has been resolved. GPCC will now reject the unsafe ciphers.

  • [30939] - When a Greeplum Database query run a function with 0 arguments, the database crashed. This issue has been resolved.

  • [30956] - When exporting the queries history page to a CSV file, the Submitted field contained the time of the query but not the date. For example, in the GPCC UI, the Submitted field would show 2020-09-13 10:25:11 but the CSV file would only show 10:25:11. This issue has been resolved.

  • [174798424] - When creating a rule condition containing more than one slice, the rule condition was ignored, and the query ran normally. This issue has been resolved.

  • [174796107] - When updating the status of a workload management rule to inactive, when the rule condition was met, the rule remained active . This issue also appeared when deactivating multiple rules in a set, and when one rule of the set had been deleted but the rest remained in the inactive status. This issue has been resolved.

  • [174795058] - On the Query History Detail page, a query’s Submitted Time did not match the one displayed on the Query List page. This issue has been resolved.

  • [174983144] - On the Query Monitor page, when the query list extended further than the window size, the Workload dropdown column did not display correctly. This issue has been resolved.

  • [174922355] - When a partition’s root table appeared in the Accuracy % Rank list, the row count column incorrectly showed a 0 (nil) value. This issue has been resolved.

  • [174767109] - When creating a rule using the Planner Cost condition, and subsequently deleting that condition by reducing the planner cost to “0”, the updated rule still showed: “planner cost is greater than [0,0]”. This issue has been resolved.

Enhancements and Changes in Greenplum Command Center 6.3.0

Workload Management

  • The Command Center interface for managing workload assignment rules has moved to a new page, Workload> Workload Mgmt. Resource group configuration remains on the Workload> Resource Groups page. See Workload Management.

  • Workload management rules can now be assigned using any combination of resource group name (or all resource groups, by default), database role, and query tag identifiers.

  • Workload management rules can include one or more conditions that must be met before the rule action is performed. Conditions are triggered after configured maximum values for CPU time, Planner Cost, Running time, Slices, or Total Disk I/O are exceeded by a query.

  • For Greenplum 6.8 or later, you can configure workload management rules to automatically move queries to a specified resource group. These rules can be created on earlier Greenplum versions, but are immediately placed in the Inactive state.

  • Command Center automatically attempts to retry applying a failed rule action 2 times, after waiting a minimum of 15 seconds between retries. You can configure the time interval using the new configuration parameter, wlm_query_cooldown_time. See Greenplum Command Center Parameters.

  • A new configuration parameter, wlm_short_query_threshold, can be used to ensure that Command Center only applies workload management rules after a query has run for at least the specified number of seconds. See Greenplum Command Center Parameters.

  • Programmatically managing workload rules using the JSON object is no longer supported.

  • The new gpmetrics tables, gpcc_wlm_rule and gpcc_wlm_log_history, were introduced to store workload rule definitions and log history. See the gpmetrics Schema Reference.

Query Monitor

  • The Query Monitor page includes a new column, CPU Time, to show the amount of system CPU consumed by each query.

  • Command Center now saves information about DDL statements (for example, CREATE and DROP statements) to history, as well as DML and queries. In earlier versions of Command Center, DDL information was displayed but not saved to history.

  • With Greenplum 6.8 or later, the Workload column on the Query Monitor page provides a drop-down menu that you can use to reassign the query to a different resource group.

  • The Blocked By column is no longer displayed for active queries. To view information about blocking transactions, use the tooltip that is displayed when the query status is Blocked. See Query Monitor.

Permissions Changes

  • Only Operator and Admin users can move queries from the Query Monitor page.
  • Only Admin users can make changes to the Recommendations and Workload pages.
  • Basic users can now view the Table Browser page.

Fixed Issues

  • [30545] The metrics collection code was updated to resolve a buffer overflow condition that could cause Greenplum Database to crash when gp_enable_query_metrics was set to “on.”

  • [30812] Resolved a problem where the rows_out value displayed an incorrect number for certain queries.

  • [173978192] Resolved a problem where the web socket connection was not rebuilt after a user attempted to login to Command Center after a previous session timed out.

  • [174275398] Command Center will now fail to start if the web server port (28080) is being used by another program.

  • [174665588] Command Center now displays the correct value for Statement Memory for resource group entries.

Known Issues

The following are known issues in the current Greenplum Command Center release.

Limitation for Defining Planner Cost in Workload Rules

When you define a workload management rule that uses the Planner Cost condition, the input field transforms your entry to a double datatype value. This can limit the ability to accurately define large planner costs that may be necessary for the GPORCA optimizer. For example, if you enter the GPORCA maximum cost value as 1457494496834852608, the actual value is converted to 1457494496834852600 for the rule. The value shown in the completed rule definition is the value that the rule enforces, and it may not be the exact value that you entered. Increase the cost value as necessary to cover the cost you want to set as the maximum.

External Updates to Workload Management Rules are Delayed

If you recreate the gp_wlm extension from outside of Command Center after you have already created workload management rules using the Command Center interface, the rules engine may not run for a period of roughly 1 hour. This behavior occurs because Command Center checks for the availability of the extension every hour. Any changes you make outside of Command Center in this situation will not be visible until Command Center checks for the extension, or until you login to Command Center and access the Workload> Workload Mgmt page.

Customized SSH Path Not Supported with the Upgrade (-u) Option

If you upgrade your Command Center installation using the gpccinstall -u option and you also specify an SSH binary using the -ssh-path <path> option, the customized SSH path will not be used during the installation and the ssh_path parameter will not be set in the app.conf file.

Calculated Root Table Size Inaccurate for Some Partitioned Tables

When viewing the Table Browser view, the calculated size for a partitioned table is incorrect if some child partitions are in different schemas than the root table.

Sorting Tables by Size on Partition List Page is Slow

If there are a large number of tables in a schema in a database, sorting the partition table list by size can take a long time to display.