Communication Error dialog may appear when selecting a VDB with hundreds of Timeflows (KBA10483)
KBA
KBA#
Issue
Selecting a VDB that contains an exceptional numbers of Timeflows (>1000) in the Manage > Datasets screen may trigger the following error from the Management web interface:
Error:
Communication Error
Command Output:
HTTP Error: 0
Status text: error
Response text: undefined
This issue has been observed when using the Chrome web browser or Chromium-related browsers, such as Microsoft Edge.
Applicable Delphix Versions
- Click here to view the versions of the Delphix engine to which this article applies
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Date Release Oct 18, 2023 16.0.0.0 Sep 21, 2023 15.0.0.0 Aug 24, 2023 14.0.0.0 Jul 24, 2023 13.0.0.0 Jun 21, 2023 12.0.0.0 May 25, 2023 11.0.0.0 Apr 13, 2023 10.0.0.0 | 10.0.0.1 Mar 13, 2023 | Mar 20, 2023 9.0.0.0 | 9.0.0.1 Feb 13, 2023 8.0.0.0 Jan 12, 2023 7.0.0.0 Releases Prior to 2023 Major Release All Sub Releases 6.0 6.0.0.0, 6.0.1.0, 6.0.1.1, 6.0.2.0, 6.0.2.1, 6.0.3.0, 6.0.3.1, 6.0.4.0, 6.0.4.1, 6.0.4.2, 6.0.5.0, 6.0.6.0, 6.0.6.1, 6.0.7.0, 6.0.8.0, 6.0.8.1, 6.0.9.0, 6.0.10.0, 6.0.10.1, 6.0.11.0, 6.0.12.0, 6.0.12.1, 6.0.13.0, 6.0.13.1, 6.0.14.0, 6.0.15.0, 6.0.16.0, 6.0.17.0, 6.0.17.1, 6.0.17.2
5.3
5.3.0.0, 5.3.0.1, 5.3.0.2, 5.3.0.3, 5.3.1.0, 5.3.1.1, 5.3.1.2, 5.3.2.0, 5.3.3.0, 5.3.3.1, 5.3.4.0, 5.3.5.0, 5.3.6.0, 5.3.7.0, 5.3.7.1, 5.3.8.0, 5.3.8.1, 5.3.9.0 5.2
5.2.2.0, 5.2.2.1, 5.2.3.0, 5.2.4.0, 5.2.5.0, 5.2.5.1, 5.2.6.0, 5.2.6.1
5.1
5.1.0.0, 5.1.1.0, 5.1.2.0, 5.1.3.0, 5.1.4.0, 5.1.5.0, 5.1.5.1, 5.1.6.0, 5.1.7.0, 5.1.8.0, 5.1.8.1, 5.1.9.0, 5.1.10.0
5.0
5.0.1.0, 5.0.1.1, 5.0.2.0, 5.0.2.1, 5.0.2.2, 5.0.2.3, 5.0.3.0, 5.0.3.1, 5.0.4.0, 5.0.4.1, 5.0.5.0, 5.0.5.1, 5.0.5.2, 5.0.5.3, 5.0.5.4
Background
When a VDB is selected in the Management web interface, one API call is issued to the Continuous Data Engine for each Timeflow in the VDB.
In typical use cases, only a very small number of Timeflows will be present for a single VDB. Old Snapshots and Timeflows are automatically removed by Snapshot Retention Policies.
VDBs capable of triggering this issue would need both frequent VDB Refresh operations, and large retention policies or a large number of Self-Service Bookmarks. For example, performing 3 VDB Refresh operations per day and retaining those snapshots for 12 months would result in a VDB with approximately 1,100 Timeflows.
If a VDB with 1,100 Timeflows is selected from the Management interface, it will issue 1,100 simultaneous API calls to the Delphix Engine.
When using the Chrome browser (or Chrome-related browsers, such as Microsoft Edge), this large number of calls will exceed a browser memory limit. To preserve memory, the browser automatically cancels requests in excess of the memory threshold, causing the Communication Error shown above.
Because this is a memory-related issue, the exact number of API calls needed to trigger it is not clear, and may vary between environments or browser versions.
Resolution
As a short term solution for working with VDBs affected by this issue, you may either:
- Perform operations using the Command Line Interface; or
- Use a different browser, such as Firefox, which can manage a larger number of API calls.
As a longer term solution, please consider whether the number of Timeflows can be reduced without affecting your business requirements. This can be done by reviewing the Refresh Policies, Retention Policies, and Self Service Bookmarks on the affected VDB.
If this issue is preventing normal operation of the Continuous Data Engine, and there is a business need to retain a large number of Timeflows, please contact Delphix Support to discuss this issue in more detail.
Delphix Engineers are aware of this issue, and this may be addressed in a future Continuous Data Engine release.
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