No Data Delivered to Backend System
In this document, we will use the information from the actual root cause analysis to make a generic view that can be used if you run into the same or a similar problem in the future. Finally, the document will describe the situation, the problem, the analysis, and the result.
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1. Situation
No data is delivered to a backend system.
2. Problem
The problem in this case was that the backend system was not receiving any data. This was caused by an unstable H2 database.
3. Analysis
3.1 Reproduction
N/A
3.2 Analysis
The problem led us to investigate the queue statistics of the flow responsible for delivering the data. Here, it was seen that data was flowing throught the queue, but in a repetitive pattern. In the runtime statistics a very high CPU was observed. Consequently, the health of the H2 database was investigated. The H2 database was processing the messages repeatedly after the connector had undergone auto-healing. Therefore, it was not processing the new messages.
4. Result
The removal and re-addition of the H2 database caused the H2 database to return to normal behavior. Afterwards, the problem did not reoccur. The resetting of the H2 database should also solve the problem. This can be done by moving to Deploy -> Architecture and pressing 'Reset H2'. Do remember that resetting the H2 database or removing and readding it will result in a loss of all the data on the database.