Here is the background:
I am currently running an ETL process on a linux server (CentOS 8) which also hosts applications which read from a local SQLite database.
At certain times when the ETL is running and writing to the SQLite database, applications are also reading from the database.
In order to avoid database locking when the SQLite database is in use by the applications, I have enabled WAL on the SQLite database so that the ETL may write to the database while applications are in use.
However there is now the following issue whereby the ETL process is unable to query the database after the connection has been established. I have logged the following information when this occurs:
The ‘shinysuite’ user runs the ETL process.
The ‘shiny’ user runs the applications.
According to the admin, these users belong to the same group.
Output from /etc/groups
First, I do not understand why the ‘shiny’ user owns the -wal file even though it only reads.
Second, I do not understand why the ETL process (‘shinysuite’) would be unable to read from the -wal file even it did not own the file.
What could be the problem here?