Note:
This topic has been translated from a Chinese forum by GPT and might contain errors.
Original topic: 从6.7升级到7.0 一致出现这个等待,500G左右的数据需要多久能升级完成,大佬们知道吗?
The main reason is that the default value of the tidb_distsql_scan_concurrency
parameter is 15, which means that each query will use 15 threads to scan data. If there are many concurrent queries, it will cause a large number of threads to be created, resulting in high CPU usage. You can try to reduce the value of this parameter to see if it can alleviate the problem.
Will this failure cause data loss?
Remember to manually set --transfer-timeout 3600 --wait-timeout 3600
later, as the default timeout is 300 seconds.
Usage:
tiup cluster upgrade <cluster-name> <version> [flags]
Flags:
--force Force upgrade without transferring PD leader
-h, --help help for upgrade
--ignore-config-check Ignore the config check result
--offline Upgrade a stopped cluster
--post-upgrade-script string (EXPERIMENTAL) Custom script to be executed on each server after the server is upgraded
--pre-upgrade-script string (EXPERIMENTAL) Custom script to be executed on each server before the server is upgraded
--transfer-timeout uint Timeout in seconds when transferring PD and TiKV store leaders, also for TiCDC drain one capture (default 600)
Global Flags:
-c, --concurrency int max number of parallel tasks allowed (default 5)
--format string (EXPERIMENTAL) The format of output, available values are [default, json] (default "default")
--ssh string (EXPERIMENTAL) The executor type: 'builtin', 'system', 'none'.
--ssh-timeout uint Timeout in seconds to connect host via SSH, ignored for operations that don't need an SSH connection. (default 5)
--wait-timeout uint Timeout in seconds to wait for an operation to complete, ignored for operations that don't fit. (default 120)
-y, --yes Skip all confirmations and assumes 'yes'
When upgrading TiKV, all the leaders on it will be transferred to other nodes. The default timeout is 300 seconds. If there are many leaders, it is easy to time out. It is recommended to modify the timeout duration.
After the upgrade, it feels like the performance of TiFlash 7.0 is similar to that of 6.5.