Michael_Lowry

Error: U00011898 Switch server mode to DWP not allowed during Zero Downtime Upgrade.

Discussion created by Michael_Lowry on Aug 31, 2017
Latest reply on Sep 29, 2017 by Michael_Lowry
This evening, we upgraded one of the two nodes of one of our AE servers from v11.2.1 to 12.0.2, using the new zero downtime upgrade capability introduced in v11.2. We are still running in compatibility mode, meaning that although the first node has been upgraded, the second node is still running the old version of the AE server.

After the upgraded v12 WPs and CPs came up, we noticed something unexpected: none of the WPs — on either node — started up as dialog work processes (DWPs). We have configured WP_MIN_NUMBER in UC_SYSTEM_SETTINGS so that a portion of work processes are dedicated to be normal work processes; the remainder though should be available to switch to dialog work processes, and normally all of the WPs not dedicated to be normal WPs switch to become DWPs. We saw no DWPs at all.

When we tried to switch one of them to DWP mode manually, we learned the reason:
Error: U00011898 Switch server mode to DWP not allowed during Zero Downtime Upgrade.
This limitation is not mentioned anywhere in the ZDU documentation. It probably should be.

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