CODEWITHSUNDEEP
grailsheroku
Mario
Mario

Reputation: 4998

connection closed error in heroku cleardb addon

i just got deploying a very simple grails app in heroku using cleardb addon, everything is fine until past some minutes and when i try to get view that has access to database i get and error message.

Here i paste a snippet from heroku logs

2014-06-04T20:12:17.511251+00:00 app[web.1]: 2014-06-04 20:12:17,511 [http-nio-38536-exec-1] ERROR util.JDBCExceptionReporter  - No operations allowed after 
connection closed.
2014-06-04T20:12:17.515181+00:00 app[web.1]: 2014-06-04 20:12:17,514 [http-nio-38536-exec-1] ERROR errors.GrailsExceptionResolver  - EOFException occurred when processing request: [GET] /user
2014-06-04T20:12:17.515187+00:00 app[web.1]: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.. Stacktrace follows:
2014-06-04T20:12:17.515190+00:00 app[web.1]:    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3166)
2014-06-04T20:12:17.515188+00:00 app[web.1]: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.

And here is my datasource production section

production {
    dataSource {
      dbCreate = "update"
      driverClassName = "com.mysql.jdbc.Driver"
      dialect = org.hibernate.dialect.MySQL5InnoDBDialect
      uri = new URI(System.env.CLEARDB_DATABASE_URL?:"//bb2c98a68a13fe:[email protected]/heroku_b28cc03a245469f?reconnect=true")
      url = "jdbc:mysql://"+uri.host+uri.path
      username = uri.userInfo.split(":")[0]
      password = uri.userInfo.split(":")[1]
    }
}

The log tell me about connection closed. i do not know what to do from here, i hope you can help me, thanks for your time

Upvotes: 2

Views: 1712

Answers (1)

Mario
Mario

Reputation: 4998

I finally got a solution to this problem, thanks for the help from heroku support team and cleardb support team, the solution was to add properties to datasource into production environment, the final code in datasource.groovy

production {
    dataSource {
      dbCreate = "update"
      driverClassName = "com.mysql.jdbc.Driver"
      dialect = org.hibernate.dialect.MySQL5InnoDBDialect
      uri = new URI(System.env.CLEARDB_DATABASE_URL?:"//bb2c98a68a13fe:[email protected]/heroku_b28cc03a245469f?reconnect=true")
      url = "jdbc:mysql://"+uri.host+uri.path
      username = uri.userInfo.split(":")[0]
      password = uri.userInfo.split(":")[1]
      properties {
        // See http://grails.org/doc/latest/guide/conf.html#dataSource for documentation
        jmxEnabled = true
        initialSize = 5
        maxActive = 50
        minIdle = 5
        maxIdle = 25
        maxWait = 10000
        maxAge = 10 * 60000
        timeBetweenEvictionRunsMillis = 5000
        minEvictableIdleTimeMillis = 60000
        validationQuery = "SELECT 1"
        validationQueryTimeout = 3
        validationInterval = 15000
        testOnBorrow = true
        testWhileIdle = true
        testOnReturn = false
        jdbcInterceptors = "ConnectionState"
        defaultTransactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED
      }
    }
}

this are the default values just do not delete it as i did it.

the reason why is this necessary is in cleardb team support answer, i paste next

6/05/2014 03:07PM wrote

Hello,

My suspicion - without troubleshooting further, just a first pass - is that your app is not managing connections properly. Your current database service tier allows a maximum of 4 simultaneous connections to the db. It is likely that your application is trying to open more connections than are allowed.

If you are using connection pooling, you must make sure that your pool is set to no larger than 4 total (and that's across all dynos if you have more than 1).

Heroku's networking times out idle connections at 60 seconds, so your database connector must be set either to have an idle timeout of no more than 60 seconds, or you must have a keep-alive interval of less than 60 (which sends a trivial query such as "SELECT 1" to keep the connection active).

We do not support grails directly, so I unfortunately can't give you specific directions of how to do that within this framework.

I hope this is helpful.

Mike ClearDB Support Team

I hope it help to someone

Upvotes: 4

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