Dashboard Graph Insert/second Value Appears Incorrect

[steed]

Hi,

I am not sure if this is a problem or if it is my own misunderstanding. I am running Monyog MONyog-3.7.6-0.glibc-2.5-42.x86_64.rpm on Centos 5.4 x86_64. I am trying to insert a lot of records into an innodb table called sbtest in a database called sbtest. I have setup monyog to sample every 5 minutes (the default)

The monyog dashboard gives the following graph:

http://img576.imageshack.us/img576/7994/monyogstatements.png

and when viewed with the per second option ticked:

http://img179.imageshack.us/img179/3500/monyogstatementspersec.png

Now, the thing is if I do a SHOW TABLE STATUS FROM `sbtest`; I get back the Rows column which shows that the table grows around 30k records a second, not 2.6. Am I misunderstanding how monyog works ? The way I understand what Monyog is presenting to me, it seems that it isnt showing the correct data.

Can anyone help/explain ?

Thanks,

Steed.

[Sayan Chaliha]

Hi Steed,

To answer your questions briefly:

— MONyog's Dashboard displays the number of statements executed on the server being monitored, and not how many records these statements modified/inserted/deleted.

— Number of records added to/removed from a table in MySQL has no direct correspondence to the number of INSERT/DELETE statements executed on the server. A single INSERT may add multiple records to a table; a single DELETE statement may delete an entire table with thousands of records — They are still counted as 1 statement.

— MONyog uses SHOW GLOBAL STATUS and SHOW GLOBAL VARIABLES to collect server-wide stats. So if you're unsure if MONyog is displaying the right stats, you could always cross-check by executing these queries directly on your MySQL server. For example, the number of INSERT statements executed on your MySQL server can be found through:

Code:

mysql> SHOW GLOBAL STATUS LIKE 'Com_insert';
+——————-+————+
| Variable_name | Value |
+——————-+————+
| Com_insert | 102384 |
+——————-+————+
1 row in set (0.00 sec)

mysql>

Add to this the value of 'Com_replace' and you effectively get the number of INSERT statements that were executed on your server.

[steed]

Thank you for clarifying this for me, I will investigate further.

[Author]

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