Date | 27 | ||||||||
Authors | Yafang Deng Jayanta Saha john o John Simmons (Deactivated) James Harris catherine.odukale (Unlicensed) | ||||||||
Status | For developmentIn progress | ||||||||
Summary |
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Impact | Delayed updates to TIS and TSS with the trainee and position information from ESR, and TIS delayed exporting outbound files to ESR. |
| Table of Contents |
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Non-technical Description
The TIS-ESR interface works with certain files being sent and received at specific times. We observed an yesterday that stopped some of these files being processed when they should have been. In order to not miss next time frame for these files we needed to ensure these files were processed before the next day’s inbound files.
The services that store information failed and a number of files were not processed. The built in alerting notified the team and after verifying the status of a number of failed individual transactions, we resolved the immediate problem and resent the instructions to process the files listed below.
in/DE_EMD_RMC_20230626_00003445.DAT
in/DE_EOE_RMC_20230626_00003645.DAT
in/DE_KSS_APC_20230625_00012753.DAT
in/DE_KSS_RMC_20230626_00003635.DAT
in/DE_LDN_APC_20230625_00012751.DAT
in/DE_LDN_APC_20230626_00012764.DAT
in/DE_LDN_DCC_20230626_00012719.DAT
in/DE_LDN_RMC_20230626_00004033.DAT
in/DE_MER_RMC_20230626_00003613.DAT
in/DE_NTH_APC_20230625_00012755.DAT
in/DE_NTH_RMC_20230626_00003858.DAT
in/DE_NWN_RMC_20230626_00003613.DAT
in/DE_OXF_APC_20230625_00012758.DAT
in/DE_OXF_RMC_20230626_00003606.DAT
in/DE_PEN_RMC_20230626_00001740.DAT
in/DE_SEV_RMC_20230626_00001488.DAT
in/DE_WES_APC_20230625_00012757.DAT
in/DE_WES_RMC_20230626_00003921.DAT
in/DE_WMD_RMC_20230626_00003753.DAT
in/DE_YHD_RMC_20230626_00003844.DAT
...
Trigger
Memory of one RabbitMQ node reached the high watermark and all the incoming traffic (including ESR, Reval, TIS, etc.) were blocked.
...
Detection
We got an on ESR-DATA-EXPORTER service in #sentry-esr channel and also in #monitoring-esr channel, we didn’t receive any notifications for ESR processing in the morning.
...
Resolution
We purged the queue
esr.queue.audit.neoto release memory of RabbitMQ and when the memory dropped below the watermark, it started to accept incoming traffic again.We downloaded all the files arriving at ESR S3 bucket on 26th/Jun, and got them uploaded and processed manually.
...
Timeline
All times in BST unless indicated
13:09 Noticed the RabbitMQ exceptions and its memory reached the high watermark. Then found there were more than 4 million message in queue
esr.queue.audit.neo.15:06 Purged
esr.queue.audit.neo, and then the memory dropped below the watermark and RabbitMQ started to accept incoming traffic again.10:26 Checked there were 20 files in total arriving at S3 bucket on 25th/Jun, and only 2 of them (DE_LDN_APC_20230626_00012764 & DE_LDN_DCC_20230626_00012719) were processed in the afternoon of 26th/Jun. Also purged the queue
esr.dlq.2022-08-19-jayandesr.dlq.2022.08.0910:40-11:00 Manually downloaded files and uploaded them again to trigger ESR processing.
5 Whys (or other analysis of Root Cause)
Why ESR files were not processed in the morning of 26th/Jun? - Because the RabbitMQ was not accepting any incoming traffic and was not able to process transactions.
Why was RabbitMQ not able to accept incoming traffic and process transactions? - Because there was not enough memory.
Why there was not enough memory in RabbitMQ? - Because it was occupied by
esr.queue.audit.neoqueue. There were more than 4 million messages in it and it ate up the resource.Why there were more than 4 million messages in
esr.queue.audit.neoqueue? - Currently, we don’t know.
...
Action Items
Action Items | Owner | Comments |
|---|---|---|
Investigate why there are so many message in Monitor the queue for a period of time to find out if there’re still rapid increasing on the number of messages. | ||
Investigate why we still have incoming messages in | ||
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Lessons Learned
Learn more knowledge about ESR.