by admin | Oct 16, 2018 | Troubleshooting
Based on “How to clean or resize the ibtmp1 file in MySQL?” This is another lesson learned in rather “hard way” – temporary tablespace on one of our instances grew so big we had problems with full disk. Fortunately both Debian and MySQL...
by admin | Jul 31, 2018 | Troubleshooting
MySQL slow log is extremely useful feature of MySQL server. But its investigation can be very painful. Mainly due to the usually huge size of it. Investigation using command line tools is usually the quickest possibility. So here are few useful commands: find longest...
by admin | Apr 25, 2018 | Troubleshooting
You can see “Errcode: 28 – No space left” in MySQL error.log for several reasons. In the past when DBAs usually lived without monitoring it could “really surprised” them that disk was full one day… 🙂 In these days I think everyone...
by admin | Feb 13, 2018 | Troubleshooting
If you try to use really big VARCHAR columns like 60000 bytes and try to index it you will see things happening… MySQL has internal limit max 65 535 bytes for combined size of all columns in the row (not counting blob and text types). But this works only for...
by admin | Jan 25, 2018 | Troubleshooting
Following errors can occur in MySQL error.log file during start-up: 2018-11-15T14:23:41.871139Z 0 [Warning] Could not increase number of max_open_files to more than 5000 (request: 25010) 2018-11-15T14:23:41.872193Z 0 [Warning] Changed limits: max_connections: 4190...
by admin | Oct 25, 2017 | Troubleshooting
If you cannot make remote connection into MySQL and you get errors like: Table ‘performance_schema.session_variables’ doesn’t exist Native table ‘performance_schema’.’session_variables’ has the wrong structure or something...