I'm using MONyog to track all queries from user, but when config connect to mysql server. I can not see any query after click start? How can I see queries in MONyog?
Reference MONyog
I guess you are referring to MONyog's Real-Time feature? In Real-Time tab MONyog executes SHOW FULL PROCESSLIST at every 1 second to get queries being executed on the MySQL server. Hence, short-lived queries (queries which takes less than 1 second) may or may not be recorded.
You can enable Performance Schema based sniffer which will record all the queries(even short lived queries). Performance Schema based sniffer makes use of the performance_schema database of the MySQL server(which is available in v5.6+).
Related
Is there any way to check the query that occurs in my MySql database?
For example:
I have an application (OTRS) that allows you to generate reports according to the frames that I desire. I would like to know which query is made by the application in the database.
Because I will use it to integrate with other reporting software.
Is this possible?
Yes, you can enable logging in your MySQL server. there are several types of logs you can use, depending on what you want to log, starting from errors only or slow queries, and to logs that write everything done on your server.
See the full doc here
Although, as Nir says, mysql can log all queries (you should be looking at the general log or the slow log configured with a threshold of 0 seconds) this will show all the queries being run; on a production system it may prove difficult to match what you are doing in your browser with specific entries in the log.
The reason I suggest using the slow query log is that there are tools available which will remove the parameters from the queries, allowing you to see what SQL code is running more frequently.
If you have some proficiency in Perl it should be straightforward to output - all queries are processed via an abstraction layer.
(Presumably you are aware that the schema is published)
I have published my website on Amazon EC2 (Singapore region) and I have used MySQL RDS instance for the data storage. Everything is working very fine except performance.
I seems that, my all queries, especially the select statement, is performing very slowly. If I check this issue on my local PC, there it is working very well. But when I am trying to get data from RDS instance, it is very slow. Some of the select statements takes 2-3 seconds to fetch data.
I have properly tuned up all table indexes, and normalized/de-normalized as required. I have made all necessary settings on RDS custom parameter group (eg. max_connection, buffer etc). I don't know if I am missing something, but it didn't work for me - performance didn't increase.
So, can someone please help me with this issue?
It is worth noting that, for whatever reason, MySQL query cache is OFF by default in RDS. We learned that the hard way ourselves this week.
This won't help performance of your initial query, but it may speed things up in general.
To re-enable query cache:
Log in to the RDS Console
Click on your RDS instance to view it's details
Edit the Database Parameter Group
Be sure to set both query_cache_size and query_cache_type
(Disclaimer: I am not a DBA so there may be additional things I'm missing here)
For me, it was nothing to do with MySQL but rather the instance type I was on t2.medium. The problem is I ran out of CPU credits because the load on the DB was too high and the balance kept going down until finally, I was getting far fewer credits hourly than were needed.
Here is what I saw in RDS CloudWatch under CPU Credit Usage:
If you have the same problem it may be time to switch to a different instance. Here is the list of instance types:
https://aws.amazon.com/rds/instance-types/
Hope this helps.
It is important to have your RDS and EC2 instances not just in the same region but also in the same availability zone to minimize the latency.
I had an API hosted in Ireland on EC2 and moved the Database to a MySQL cluster in Virginia USA that we had set up for another project and the round trip on every SQL query made the API unusable.
RDS MySQL performance can be increased in following ways assuming the system has more read ratio:
Use Larger instance types, they come with better NW bandwidth. Example AWS Quadruple EXL comes with 1,000 Mbps bandwidth.
Use PIOPS storage you can extract 12,500 IOPS of 16KB from MySQL DB
If lots of read is performed, add one or more Read Replica's to increase read performance
Apply standard practices like: Tune the queries, apply the indexes etc
First i highly recommend to look over these queries using
SHOW FULL PROCESSLIST
You can read more about it on SHOW FULL PROCESSLIST
This will show you the time each query take.
Then you can use
EXPLAIN
You can read more about it on EXPLAIN
This will show you if you need some enhancement on your queries
You can check where the query is taking time by making use of profiling. Use the below query:
set profiling=1
execute your select query
show profile
This will tell you about the status of the query and where the query is spending its time. If the sum of all the time returned by the profiling is less than the actual execution time of the query, then maybe other factors like Network bandwidth may be the cause of it.
Always should deploy source and rds in the same AWS availability zone for lower network latency and Should create a private endpoint link in VPC for RDS to connect RDS endpoint through the internal network instead of routing through the internet.
Reference: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/vpc-interface-endpoints.html
I found that after migrating to RDS all my database Indexes are gone! They weren't migrated along with the schema and data. Make sure you're indexes are there.
I want to check the performance of my database in mysql. I googled and came to know about show full processlist etc commands, but not very clear. i just want to know and calaculate the performance of database in terms of how much heap memory it is taking and other such.
Is there any way to know and assess the performance of the database. so that I can optimize and improve the performance.
Thanks in advance
The basic tool is MySQL Workbench which will work with any recent version of MySQL. It's not as powerful as the enterprise version, but is a great place to start.
The configuration can be exposed with SHOW VARIABLES and the current state of the system is exposed through SHOW STATUS. These status numbers are what ends up being graphed in most tools.
Don't forget that you can do a lot of monitoring on the application side, turning on database logs for instance. Barring that you can enable the "slow query" log in MySQL to check which queries are having the most impact. These can then be diagnosed with EXPLAIN.
Download mysql enterprise tools. They will allow you to monitor load on the server as well as performance of individual queries.
You can use open source tools from Percona called as Percona Toolkit and start using some useful tools which can help you in Efficiently archive rows, Find duplicate indexes, Summarize MySQL servers, Analyze queries from logs and tcpdump and Collect vital system information when problems occur.
You can try experimenting with Performance_Schema tables avialable in MySQL v5.6 onwards which can give a detailed information of query, database statistics.
http://www.markleith.co.uk/2012/07/04/mysql-performance-schema-statement-digests/
I have around 3 websites residing in a server which is being shared with other teams. I have been notified that there is a huge increase in CPU usage and we need to lower it down. I doubt my websites are causing this.
I have been using SHOW FULL PROCESSLIST in MySQL and 90% of the time shows queries from other databases. But I think executing multiple SHOW FULL PROCESSLIST commands is not enough proof. How can I verify that my databases aren't CPU hogs?
If you suspect that its a MySQL query, try inspecting the MySQL Slow Query Log. The log will help you identify queries that take long time to execute. You can then copy-paste the query text into a MySQL query session, execute it and observe the CPU usage.
You may also want to install different MySQL release, that allows to track exact user statistics and some other things:
http://www.mysqlperformanceblog.com/2008/07/16/mysql-releases-with-percona-patches/
I am about to begin developing a logging system for future implementation in a current PHP application to get load and usage statistics from a MYSQL database.
The statistic will later on be used to get info about database calls per second, query times etc.
Of course, this will only be used when the app is in testing stage, since It will most certainly cause a bit of additional load itself.
However, my biggest questionmark right now is if i should use MYSQL to log the queries, or go for a file-based system. I'll guess that it would be a bit of a headache to create something that would allow writings from multiple locations when using a file based system to handle the logs?
How would you do it?
Use the general log, which will show client activity, including all the queries:
http://dev.mysql.com/doc/refman/5.1/en/query-log.html
If you need very detailed statistics on how long each query is taking, use the slow log with a long_query_time of 0 (or some other sufficiently short time):
http://dev.mysql.com/doc/refman/5.1/en/slow-query-log.html
Then use http://www.maatkit.org/ to analyze the logs as needed.
MySQL already had logging built in- Chapter 5.2 of the manual describes these. You'll probably be interested in The General Query Log (all queries), the Binary Query Log (queries that change data) and the Slow log (queries that take too long, or don't use indexes).
If you insist on using your own solution, you will want to write a database middle layer that all your DB calls go through, which can handle the timing aspects. As to where you write them, if you're in devel, it doesn't matter too much, but the idea of using a second db isn't bad. You don't need to use an entirely separate DB, just as far as using a different instance of MySQL (on a different machine, or just a different instance using a different port). I'd go for using a second MySQL instance instead of the filesystem- you'll get all your good SQL functions like SUM and AVG to parse your data.
If all you are interested in is longer-term, non-real time analysis, turn on MySQL's regular query logging. There are tons of tools for doing analysis on the query-logs (both regular and slow-query), giving you information about the run-times, average rows returned, etc. Seems to be what you are looking for.
If you are doing tests on MySQL you should store the results in a different database such as Postgres, this way you won't increase the load with your operations.
I agree with macabail but would only add that you could couple this with a cron job and a simple script to extract and generate any statistics you might want.