With the comment filter it is possible to define comments that are injected before the actual statements. These comments appear as sql comments when they are received by the server.
The Comment filter requires one mandatory parameter to be defined.
injectType: string
Mandatory: Yes
Dynamic: Yes
A parameter that contains the comment injected before the statements. There is also defined variable $IP that can be used to comment the IP address of the client in the injected comment. Variables must be written in all caps.
as comment.
The following configuration adds the IP address of the client to the comment.
In this example when MaxScale receives statement like:
It would look like
when received by server.
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[MyComment]
type=filter
module=comment
inject="Comment to be injected"
[MyService]
type=service
router=readwritesplit
servers=server1
user=myuser
password=mypasswd
filters=MyComment[IPComment]
type=filter
module=comment
inject="IP=$IP"
[MyService]
type=service
router=readwritesplit
servers=server1
user=myuser
password=mypasswd
filters=IPCommentSELECT user FROM people;/* IP=::ffff:127.0.0.1 */SELECT user FROM people;