Interacting with the database

SQL operations

Create table:

• If the given table does not exist, AxoSyslog tries to create it with the given column types.

• The AxoSyslog application automatically creates the required tables and columns, if the user account used to connect to the database has the required privileges.

• If AxoSyslog cannot create or alter a table, it tries to do it again when it reaches the next time-reopen().

Alter table:

• If the table structure is different from given structure in an existing table, AxoSyslog tries to add columns in this table but never will delete or modify an existing column.

• If AxoSyslog cannot create or alter a table, it tries to do it again when reach the next time-reopen().

• The AxoSyslog application requires read and write access to the SQL table, otherwise it cannot verify that the destination table exists.

Insert table:

• Insert new records in a table.

• Inserting the records into the database is performed by a separate thread.

• The AxoSyslog application automatically performs the escaping required to insert the messages into the database.

• If insert returns with error, AxoSyslog tries to insert the message +two times by default, then drops it. Retrying time is the value of time-reopen().

Encoding

The AxoSyslog application uses UTF-8 by default when writes logs into database.

Start/stop and reload

Start:

• The AxoSyslog application will connect to database automatically after starting regardless existing incoming messages.

Stop:

• The AxoSyslog application will close the connection to database before shutting down.

Possibility of losing logs:

• The AxoSyslog application cannot lose logs during shutting down if disk buffer was given and it is not full yet.

• The AxoSyslog application cannot lose logs during shutting down if disk buffer was not given.

Reload:

• The AxoSyslog application will close the connection to database if it received SIGHUP signal (reload).

• It will reconnect to the database when it tries to send a new message to this database again.

Macros:

The value of ${SEQNUM} macro will be overridden by sql driver regardless of local or relayed incoming message.

It will be grown continuously.