Hi,
we try to gather the number of current connections of an MySQL database via the MySQL v2 sensor.
Unfortunatelly the received results are not matching with the expected results and therefore we assume the query do not work proper.
We have tried two different methods:
1. select count(*) from information_schema.PROCESSLIST
Under MySQL it returns the total number of connection in a single line and column. When we use the sensor to process the data it returns always 5.
2. select * from information_schema.PROCESSLIST where information_schema.PROCESSLIST.host not like "server%"
Under MySQL it returns the correct number of line (without the local server%) When we use the sensor to evaluate the rows of the query it returns always 1
What will be the database schema we need to trigger as a target? Is it information_schema or the one we created?
For the moment i did a workaround and process the query via comandline to an outfile and count the raws. Thats fine but may it can be easier to achieve with someones help.
Any ideas?
Thanks, Sascha
Article Comments
Dear Arne,
thanks a lot for your reply.
It is very helpful to have the option you have mentioned.
The system returns with a access denied error due to missing permissions as follows:
Authentication to host x.x.x.x for user " using method 'mysql_native_password' failed with the message: Access denied for user "@'PRTGASSET' (using password: NO)
Unfortunately I can not find a switch to provide username and password and anonymous user on MySQL is enabled.
Additional information are much appreciated.
Thanks, Sascha
Jan, 2017 - Permalink
Dear Sascha
Please check if you entered the credentials into the according fields to connect to the MySQL database, including the password. The SQLv2.exe form should have fields to provide the credentials.
Jan, 2017 - Permalink
Thanks Arne,
i found the option to enter username and password - seems to was blind.
However, i have tested several queries and they are returning the wrong values compared to the queries within mysql itself.
This seems to be related only to queries affecting the information_schema database itself. For example the query "select * from information_schema.processlist" returns the following:
| ID | USER | HOST | DB | COMMAND | TIME | STATE | INFO |
|---|---|---|---|---|---|---|---|
| 8906 | root | PRTGASSET:55742 | information_schema | Query0 | select * from information_schema.processlist |
Looks like the result gets filterd for connections comming from the PRTGSERVER itself instead of displaying all hosts.
Thanks, Sascha
Jan, 2017 - Permalink
You could try the following:
SET @servername = @prtg; SHOW FULL PROCESSLIST WHERE Host NOT LIKE %@servername%;
using %server as input parameter. Does that work?
Jan, 2017 - Permalink
Unfortunately the query is not working at all, but when I change the query to SHOW FULL PROCESSLIST it still just Returns 1 row with the PRTG - Servername only. The results looks to be limited to the query initiator source....
It is strange, isnt it?
Jan, 2017 - Permalink
When I'm opening two SQL clients (i.e. two connections), I do get indeed two lines...have you tried that yet?
Jan, 2017 - Permalink
We have about 45 Clients that use the MySQL permanent. Usually it is between 15 and 40 concurrent connections. Therefore, when I querythe processlist from MySQL Workbench it shows all connections, but only not from SQLv2. I don´t understand why SQLv2 just considers the PRTG server in the query...
Jan, 2017 - Permalink
Could you try SHOW FULL PROCESSLIST; as query? Does that return a number other than 1?
Feb, 2017 - Permalink
I am afraid, I already tried this but sqlv2.exe still returns just one row...
...I have tried to start the application from another device but it cant run without prtg installation.
BTW, the version of sqlv2.exe is 0.1.0.27652. Any update available?
Feb, 2017 - Permalink
Nope, that's the latest. But the problem seems to be related to the privileges of the user you're using. Make sure that the same has the PROCESS privilege globally. Can you check that? If you need to set it, please remember to flush the privileges afterwards in order for them to be actually updated.
Feb, 2017 - Permalink
Perfect, it was the right direction... somehow this user is not able to process the query properly, even with right permissions. I changed to a different user and all looks fine from the sqlv2.exe now. I will give it a shot in PRTG now and return in case of ongoing trouble...
...many thanks so far!
Feb, 2017 - Permalink
something similar happened to me, the solution was to eliminate the character of the password since it is a reserved symbol
Nov, 2018 - Permalink
Dear Sascha
Please manually test the sensor and check the result of your query. The executable is "SQLv2.exe", usually located in C:\Program Files (x86)\PRTG Network Monitor\Sensor System. Please start the file, configure the options according to your MySQL server and perform the query. Are you getting the expected output table?
Jan, 2017 - Permalink