Hi Jeremy,

I think that closing the connection after the information is retrieved would be the right course of action. I recall a similar think needed to be done for the CLAS software. The database at Jlab is also used by other experiments, so we need to keep that in account as well. 
If we close the connection after the information is retrieved, and then later data needs to be stored or more needs to be retrieved, it should be easy to re-connect.

Best,
Maurik

On Dec 26, 2014, at 7:08 AM, McCormick, Jeremy I. <[log in to unmask]> wrote:

I believe that should be tunable on the MySQL db via max_connections setting, but would need to talk to the admin about changing it.  Around 100 is probably the default.  How many simultaneous connections would we need?

Also, it should be possible to close the connection in the db manager after conditions setup is done or make this an optional part of the configuration.

On Dec 25, 2014, at 11:48 PM, Graham, Mathew Thomas <[log in to unmask]> wrote:


We’re getting a "Too many connections” error when running production…there are only ~100 jobs running.  Is this a real limit or just a parameters we can increase (or something else). 

Thanks, Matt


Fri Dec 26 00:41:28 EST 2014 :: DatabaseConditionsManager :: CONFIG :: host jmysql.jlab.org
Fri Dec 26 00:41:28 EST 2014 :: DatabaseConditionsManager :: CONFIG :: port 3306
Fri Dec 26 00:41:28 EST 2014 :: DatabaseConditionsManager :: CONFIG :: user hpsuser
Fri Dec 26 00:41:28 EST 2014 :: DatabaseConditionsManager :: CONFIG :: database hps_conditions
Exception in thread "main" java.lang.RuntimeException: Failed to connect to database: jdbc:mysql://jmysql.jlab.org:3306/
        at org.hps.conditions.database.ConnectionParameters.createConnection(ConnectionParameters.java:122)
        at org.hps.conditions.database.DatabaseConditionsManager.openConnection(DatabaseConditionsManager.java:150)
        at org.hps.conditions.database.DatabaseConditionsManager.initialize(DatabaseConditionsManager.java:293)
        at org.hps.conditions.database.DatabaseConditionsManager.setDetector(DatabaseConditionsManager.java:240)
        at org.hps.evio.EvioToLcio.run(EvioToLcio.java:272)
        at org.hps.evio.EvioToLcio.main(EvioToLcio.java:99)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
        at com.mysql.jdbc.Util.getInstance(Util.java:386)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1112)
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2486)
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
        at java.sql.DriverManager.getConnection(DriverManager.java:579)
        at java.sql.DriverManager.getConnection(DriverManager.java:190)
        at org.hps.conditions.database.ConnectionParameters.createConnection(ConnectionParameters.java:119)


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