Note:
This topic has been translated from a Chinese forum by GPT and might contain errors.
Original topic: 短暂宕机
【TiDB Usage Environment】Test Environment / Test / Poc
【TiDB Version】v7.1.1
【Reproduction Path】Operations performed that led to the issue
【Encountered Issue: Symptoms and Impact】
Brief downtime, client unable to connect. Numerous tiflash error logs.
【Resource Configuration】Navigate to TiDB Dashboard - Cluster Info - Hosts and take a screenshot of this page
【Attachments: Screenshots/Logs/Monitoring】
Could you please help analyze the cause?
Two TiKV, three TiDB, one TiFlash? What should be the machine configuration?
3 virtual machines, each with 8 cores and 32GB of RAM.
How many replicas are there for 2 KVs? There is no high availability. If one KV fluctuates, the entire cluster becomes unavailable.
There is only one TiFlash.
I have only tried deploying 1 TiKV and 3 TiKV with fewer than 3 TiKV; I haven’t tried 2 TiKV to see if it’s stable. It seems to be an issue with the 114 host? You can try evicting the TiDB from 114 and then check the host logs.
The issue is on 114, where tiflash is installed. Should we kill the tidb on 114? Or should we add another tiflash node?
From the screenshot, it is clear that your TiFlash CPU bottleneck is very obvious. What I mean is to remove the TiDB server on 114 and keep only one TiFlash;
If you test again, you can use dstat 1 to check the host’s load;
Also, I didn’t see any crash restart records in the TiFlash logs. Could you send them if it’s convenient?
From your screenshot, it looks like TiFlash is constantly restarting.
I understood it as I manually restarted it
The log is over 900MB, which is a bit large.
Cut it and see if there are any keywords like start / out of / shutdown / abort inside.
start(upload://x3TmT4BBWQaONulkxmcQgcJK0Ji.rar) (13.7 MB)
I can’t see any issues, except for the log truncation and TiFlash startup records
Did you only connect one TiDB server? If so, could you send the TiDB server log and PD log for the problematic period?
I will check the configuration file of the program.
Can I see the resource topology diagram?