xSQL Recover

It is possible to direct xSQL to connect to an existing database in shared memory.

For an overview see page xSQL Server Instrumentation

Specifying the command line option -daemon directs xSQL to connect to an existing database in shared memory (instead of creating new one) and start as a Remote SQL server for the database. This is especially useful for recovering a shared memory database opened by xSQL or another application, and then left “orphaned” when the xSQL process terminates ungracefully or the other application crashes.

For example, suppose the database was created with the following command:

 
    ./xsql -size 100m -shared -dbname mydb -p 12345
     

Then the xSQL process is ungracefully terminated for some reasons. To restore remote access to the database we can start xSQL as follows:

 
    xsql mydb -recovery -p 12345 -daemon