Alma AP01 - RCA - August 5, 2020
This document serves as a Root Cause Analysis for the Alma service interruption experienced by Ex Libris customers on August 5, 2020
The goal of this document is to share our findings regarding the event, specify the root cause analysis, outline actions to be taken to solve the downtime event, as well as preventive measures Ex Libris is taking to avoid similar cases in future.
Intermediate service interruptions were experienced by Ex Libris customers served by the Alma AP01 instance at our Singapore Data Center during the following time period:
August 5th , 2020 from 11:46 AM until 12:12 PM Singapore time
During the event, the service was unavailable for the environment.
Root Cause Analysis
Ex Libris Engineers investigated this event to determine the root cause analysis with the following results:
The event was caused by a statistics gathering process on a DB table with high concurrency, which eventually caused a service disruption.
During the events On May 20th & 26th Ex Libris engineers fixed all DB tables that were known with problematic routine statistics gathering.
On this latest occurrence another table was found to cause this and was fixed as well.
Technical Action Items and Preventive Measures
Ex Libris has taken the following action and preventive measures to avoid such an occurrence in future:
- Ex Libris engineers did a further analysis for all the tables that may cause same system disruption due to high concurrency.
Following this analysis it was decided to move statistics gathering of the new DB tables that were found to the night time.
This, in addition to the tables which were already handled on the event of May 26th.
This fix was applied on Aug 5th immediately after the service disruption
Ex Libris is committed to providing customers with prompt and ongoing updates during Cloud events. Ongoing and prompt updates on service interruptions appear in the system status portal at this address: http://status.exlibrisgroup.com/
These updates are automatically sent as emails to registered customers.