Query in PostgreSQL became slow and then got better on its own - why?
I want to better understand how to debug and fix performance issues in PostgreSQL.
I have a query that usually costs 1 second to run. However, for some reason, it started taking 30 seconds to run for a period of time! After some minutes and some explain analyze invocations, it went back to normal. I didn't do anything to fix it, nor did I understand why it got better all of a sudden.
How do I debug a problem like this? What kind of logging and instrumentation should I have in place to understand what caused this and how to fix it?
postgresql postgresql-performance postgresql-10
asked Apr 19 '18 at 1:46
ivarecivarec
948
bumped to the homepage by Community♦ 19 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
add a comment |
I want to better understand how to debug and fix performance issues in PostgreSQL.
I have a query that usually costs 1 second to run. However, for some reason, it started taking 30 seconds to run for a period of time! After some minutes and some explain analyze invocations, it went back to normal. I didn't do anything to fix it, nor did I understand why it got better all of a sudden.
How do I debug a problem like this? What kind of logging and instrumentation should I have in place to understand what caused this and how to fix it?
postgresql postgresql-performance postgresql-10
asked Apr 19 '18 at 1:46
ivarecivarec
948
bumped to the homepage by Community♦ 19 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
1
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
1
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41
add a comment |
I want to better understand how to debug and fix performance issues in PostgreSQL.
I have a query that usually costs 1 second to run. However, for some reason, it started taking 30 seconds to run for a period of time! After some minutes and some explain analyze invocations, it went back to normal. I didn't do anything to fix it, nor did I understand why it got better all of a sudden.
How do I debug a problem like this? What kind of logging and instrumentation should I have in place to understand what caused this and how to fix it?
postgresql postgresql-performance postgresql-10
asked Apr 19 '18 at 1:46
ivarecivarec
948
I want to better understand how to debug and fix performance issues in PostgreSQL.
I have a query that usually costs 1 second to run. However, for some reason, it started taking 30 seconds to run for a period of time! After some minutes and some explain analyze invocations, it went back to normal. I didn't do anything to fix it, nor did I understand why it got better all of a sudden.
How do I debug a problem like this? What kind of logging and instrumentation should I have in place to understand what caused this and how to fix it?
postgresql postgresql-performance postgresql-10
postgresql postgresql-performance postgresql-10
asked Apr 19 '18 at 1:46
ivarecivarec
948
asked Apr 19 '18 at 1:46
ivarecivarec
948
edited Apr 19 '18 at 2:04
ivarec
asked Apr 19 '18 at 1:46
ivarecivarec
948
asked Apr 19 '18 at 1:46
ivarecivarec
948
asked Apr 19 '18 at 1:46
ivarecivarec
948
948
bumped to the homepage by Community♦ 19 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
bumped to the homepage by Community♦ 19 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
1
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
1
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41
add a comment |
1
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
1
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41
1
1
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
1
1
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41
add a comment |
1 Answer
1
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oldest
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It is a very broad question, even more so as you give absolutely no details about your setup and kind of database (volume, type of queries, active connections, size of RAM, dedicated server or not, etc.)
You can start by enabling PostgreSQL to log slow queries, see the log_min_duration_statement in the configuration. That will give you historical data that you would then be able to analyze and maybe correlate with other things (like from the list of @Vérace)
You will then have various tools to help, as described on https://wiki.postgresql.org/wiki/Logging_Difficult_Queries :
- pgFouine
- PQA
- EPQA
- pgsi
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
add a comment |
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It is a very broad question, even more so as you give absolutely no details about your setup and kind of database (volume, type of queries, active connections, size of RAM, dedicated server or not, etc.)
You can start by enabling PostgreSQL to log slow queries, see the log_min_duration_statement in the configuration. That will give you historical data that you would then be able to analyze and maybe correlate with other things (like from the list of @Vérace)
You will then have various tools to help, as described on https://wiki.postgresql.org/wiki/Logging_Difficult_Queries :
- pgFouine
- PQA
- EPQA
- pgsi
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
add a comment |
It is a very broad question, even more so as you give absolutely no details about your setup and kind of database (volume, type of queries, active connections, size of RAM, dedicated server or not, etc.)
You can start by enabling PostgreSQL to log slow queries, see the log_min_duration_statement in the configuration. That will give you historical data that you would then be able to analyze and maybe correlate with other things (like from the list of @Vérace)
You will then have various tools to help, as described on https://wiki.postgresql.org/wiki/Logging_Difficult_Queries :
- pgFouine
- PQA
- EPQA
- pgsi
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
add a comment |
It is a very broad question, even more so as you give absolutely no details about your setup and kind of database (volume, type of queries, active connections, size of RAM, dedicated server or not, etc.)
You can start by enabling PostgreSQL to log slow queries, see the log_min_duration_statement in the configuration. That will give you historical data that you would then be able to analyze and maybe correlate with other things (like from the list of @Vérace)
You will then have various tools to help, as described on https://wiki.postgresql.org/wiki/Logging_Difficult_Queries :
- pgFouine
- PQA
- EPQA
- pgsi
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
It is a very broad question, even more so as you give absolutely no details about your setup and kind of database (volume, type of queries, active connections, size of RAM, dedicated server or not, etc.)
You can start by enabling PostgreSQL to log slow queries, see the log_min_duration_statement in the configuration. That will give you historical data that you would then be able to analyze and maybe correlate with other things (like from the list of @Vérace)
You will then have various tools to help, as described on https://wiki.postgresql.org/wiki/Logging_Difficult_Queries :
- pgFouine
- PQA
- EPQA
- pgsi
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
answered May 2 '18 at 15:56
Patrick MevzekPatrick Mevzek
6641416
6641416
add a comment |
add a comment |
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1
System busy overall? Table(s) undergoing a large update? Large analytic type query being run? The Gods not appreciating your invocations? :-) On a more serious note, this is the reason you should have monitoring software installed before problems arise! Do you have anything like sysstat or nagios or similar?
– Vérace
Apr 19 '18 at 3:14
No. Just some simple logs in pg. Was considering using the ELK stack to get all kinds of verbose logs
– ivarec
Apr 19 '18 at 3:15
1
Have you considered the excellent (and Open Source) sysstat tools?
– Vérace
Apr 19 '18 at 3:34
Go this link. It may help you..! dbrnd.com/2016/02/…
– Ramanna Gunde
Apr 19 '18 at 5:41