Revisions to Opening MySQL connection is sometimes very slow

Bumped by Community user

occurred Mar 7, 2017 at 10:50

Bumped by Community user

occurred Feb 1, 2017 at 12:19

Bumped by Community user

occurred Jan 1, 2017 at 2:31

Bumped by Community user

occurred Nov 27, 2016 at 20:40

Bumped by Community user

occurred Oct 28, 2016 at 9:26

Bumped by Community user

occurred Sep 25, 2016 at 15:00

Bumped by Community user

occurred Aug 8, 2016 at 20:44

Bumped by Community user

occurred Jul 2, 2016 at 17:11

added 148 characters in body

Source Link

edited May 19, 2016 at 6:36

bdem

131
1
1
3

I have a very weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

QUESTIONS

How can I debug this issue and find the cause?
Has anyone seen this behaviour before?

EDIT: We've norrowed down the issue to the actual servers. Don't know if it's a hardware problem or an OS/kernel/drivers one. Still investigating.

I have a very weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

QUESTIONS

How can I debug this issue and find the cause?
Has anyone seen this behaviour before?

I have a very weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

QUESTIONS

How can I debug this issue and find the cause?
Has anyone seen this behaviour before?

EDIT: We've norrowed down the issue to the actual servers. Don't know if it's a hardware problem or an OS/kernel/drivers one. Still investigating.

added 23 characters in body

Source Link

edited Mar 30, 2016 at 2:43

RolandoMySQLDBA

184.4k
33
323
531

I have a very weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

How can I debug this issue and find the cause? Has anyone seen this behaviour before?QUESTIONS

How can I debug this issue and find the cause?

Has anyone seen this behaviour before?

I have a weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

How can I debug this issue and find the cause? Has anyone seen this behaviour before?

I have a very weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

QUESTIONS

How can I debug this issue and find the cause?

Has anyone seen this behaviour before?

added 114 characters in body

Source Link

edited Mar 27, 2016 at 10:15

bdem

131
1
1
3

I have a weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

How can I debug this issue and find the cause? Has anyone seen this behaviour before?

I have a weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

How can I debug this issue and find the cause? Has anyone seen this behaviour before?

I have a weird issue with an older MySQL server (v5.0.45) and a Java application.

From time to time getting a connection from the database takes 7 seconds, 15 seconds, 30 seconds etc (most of them are 15 seconds) or sometimes times out. This happens just from time to time. I don't see a pattern when it does happen. The rest of the time connections are created in 2-3 milliseconds.

The database is running on Linux CentOS 6.4. The servers that have issues while connecting are on Linux CentOS 7. I'm using the latest MySQL connector (currently at v5.1.38), Java 8, with a connection pool (be it that of Tomcat or c3p0) or with no connection pool (just opening and closing connections), server in load or with few clients, a few simultaneous connections or up to 100 connections. It's the same result.

Multiple applications on multiple servers connect to this database. Only on two of them this occurs, the rest have no issues, the network seems fine, the other machines are in the same network.

How can I debug this issue and find the cause? Has anyone seen this behaviour before?