My organization asked our team to use this new tool AppDynamics for better performance testing results and reports.
For that I have to attach javaagent with running jvm, on their community this step
java -Xbootclasspath/a:<path_to_jdk>/lib/tools.jar -jar
/<agent_home>/javaagent.jar <jvm_process_id>
is given to attach the javaagent with running jvm.
However when I run the same I get following result on cmd (Using windows-8 64 bit)
>Attaching to VM [6616]
java.lang.reflect.InvocationTargetException
Caused by: java.io.IOException: no such process
Exception in thread "main" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
Caused by: java.lang.reflect.InvocationTargetException
Caused by: java.io.IOException: no such process
This is the link of their documentation.
The problem with this approach is you'll have to manually do that each time. I would highly recommend just configuring your app server to automatically load the AppDynamics agent. Another option is using the universal agent, which does auto-attach: https://docs.appdynamics.com/display/PRO43/Install+the+Universal+Agent Doing this one off attach is never really a good idea, as you'll have to get the PID each time.
The error indicates that you are probably not running the attach as the same user the JVM is running under, but it could also be permissions or something else as well, hence I would use the methods that work all the time :)
Related
After our application redeployment, we sometimes see a problem when the whole GORM stops working with a weird reason
25-Apr-2021 07:00:45.351 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 48663 ms
25-04-2021 07:00:47 ERROR org.springframework.boot.context.web.ErrorPageFilter - Forwarding to error page from request [/api/<any request>] due to exception [No row with the given identifier exists: [com.test.auth.Role#1001]]
org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.test.auth.Role#1001]
at org.hibernate.internal.SessionFactoryImpl$1$1.handleEntityNotFound(SessionFactoryImpl.java:253)
at org.hibernate.proxy.AbstractLazyInitializer.checkTargetState(AbstractLazyInitializer.java:262)
at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:176)
at org.grails.orm.hibernate.proxy.SimpleHibernateProxyHandler.unwrapProxy(SimpleHibernateProxyHandler.java:79)
at org.grails.orm.hibernate.cfg.GrailsHibernateUtil.unwrapProxy(GrailsHibernateUtil.java:390)
at org.grails.orm.hibernate.cfg.HibernateUtils$_handleLazyProxy_closure1.doCall(HibernateUtils.groovy:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
...
This problem appears randomly and can be raised by any first API request (or Quartz job run) after redeployment and can be related to any domain class in the system.
The data is correct in DB and all "native" SQL queries work without any problems.
We have no locks on DB (can do any SQL query to any mentioned table) and ~10 instances of Grais web services connected to the same DB. Also, we have
dbCreate: none
for all instances
Any thoughts about the possible reason? This issue is causing us tremendous problems during the deployment process.
Grails version 3.1.16
MySQL 5.7 (Aurora)
Here is the log of this exception:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 1,409,240 milliseconds ago. The last packet sent successfully to the server was 1,409,267 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
at com.mysql.jdbc.MysqlIO.nextRowFast(MysqlIO.java:2229)
at com.mysql.jdbc.MysqlIO.nextRow(MysqlIO.java:1989)
at com.mysql.jdbc.MysqlIO.readSingleRowSet(MysqlIO.java:3410)
at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:470)
at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:3112)
at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:2341)
...
Caused by: java.io.EOFException: Can not read response from server. Expected to read 7 bytes, read 5 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3011)
at com.mysql.jdbc.MysqlIO.nextRowFast(MysqlIO.java:2212)
I know this exception is quite normal, and I've googled it and got a lot of solutions. However, none of those solutions fix my problem. Well, it's just a simple java application, not a java web application, and I didn't use any connecting pool but simply used JDBC. My mysql version is 5.7.12. And the mysql is running on a windows server, while the java application is running on linux. I have checked the 'wait_timeout' for mysql and it's 28800, which is much larger than 1409240 ms. So the problem should probably not be caused by this issue. I've also checked the tcp connection wait time on my linux, it's 7200s, still much bigger than 1409240 ms. I also tried add '?autoReconnect=true' to the JDBC url, but it still made no difference. And I'm sure that there is nothing wrong with the accessibility of my server, cause the connection does work for several minutes before the problem occurs.I've almost tried any thing I can do. However, the problem still persists. What should I do? Is there any posibility that the problem is caused by the windows firewall?
edit:
This problem occurs when executing a SELECT query tries to select all data items from a table whose size is 10.9 G. Maybe this table is just too big so that the sentence ResultSet rs = stmt.executeQuery(sql); cannot be done. But I've checked the 'max_execution_time' variable of mysql, it's set to 0, indicating there is no restriction of execution time.
Welcome to TCP/IP. Lots of things can cause loss of a TCP connection, especially one that has been idle for a while. One such thing, as you mention, is a firewall. The connection can be knocked down by some network entity even if both the client and the server agree it should be kept alive. Connection loss likelihood goes up when client and server are not on the same local network.
Figuring out why means doing lots of packet monitoring at various places in the network. That can use up a lot of time and effort and not teach you much. Plus, learning to read wireshark output is a real task.
Most client-server programmers who need long-lasting connections use some kind of keepalive operation to avoid having the connection sit idle for too long. Keepalive operations send something and get something back. In your case you could do this the easy way by issuing a SELECT NOW() query (or some other round-trip no-op) once every minute or two while your client sits otherwise idle.
The best way to handle this kind of thing is to open the database connection when you need it, then close it when you're done. If you use the connection pooling feature you can open and close your pooled connection upon every query, and still avoid churning the physical connections. The JDBC connector and MySQL server code are optimized for this approach; it is probably the best way to go.
I had com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure reading more on the error message I realized it had to do with my SSL setting in the connection string.
When you have SSL enabled in your connection string for MySQL.Please make sure your date and time are correct or in sync with the current date. If not the connection will be hit with javax.net.ssl.SSLHandshakeException resulting in The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
. prompting you to do something about your date. This is how I solved mine. I had to set my date and time correctly. Sometimes the error messages say a lot about the problem.
We are migrating some websites onto a cloud infrastructure running Windows 2008 virtual machines. These websites all run on ColdFusion with MySQL databases. They currently are running in our CoLo with no problems. Additionally, they are running on our development network in our offices with no problems.
We are setting up our cloud to match as closely as possible the configuration we currently use which is, essentially, CF10 + IIS on one server and MySQL on a separate machine. We are 99% finished and most things are running great. However....
We have run into a couple, as in 2, places where we click a link/button and are greeted with:
Error Executing Database Query.
Communications link failure The last packet successfully received from the server was 0 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
Scanning the stack-trace I also find:
Caused by: java.net.SocketException: Connection reset
The communications link error is ALWAYS: 0ms.
What's most puzzling is the Queries that seem to be causing this are simple queries that are used ALL OVER the sites with no problems. Why they are failing at hese 2 particular places has us at wits end.
Our only clue is, looking at the CF Error description of what scripts are called, we can see the script where the query is failing is getting called twice? For example, one of the occurences is in our Application file:
>The error occurred in D:/Our_Web_Sites/oursite/Application.cfm: line 73
>Called from D:/Our_Web_Sites/oursite/Application.cfm: line 17
>Called from D:/Our_Web_Sites/oursite/Application.cfm: line 1
>Called from D:/Our_Web_Sites/oursite/Application.cfm: line 73
>Called from D:/Our_Web_Sites/oursite/Application.cfm: line 17
>Called from D:/Our_Web_Sites/oursite/Application.cfm: line 1
We can find nothing in our CF code that would be causing the script to be called twice so our guess is the first call is failing on the Query so CF tries again...only to fail and error.
Googling this issue I've found lots of posts about changing the MySQL timeouts. None of those worked and I didn't expect them to since what we're dealing with doesn't appear to be a timeout issue. These pages fail each and every time.
The closest we've come to a solution came from this blog posting:
http://www.talkingtree.com/blog/index.cfm/2011/1/12/Validation-Query-for-MySQL-communications-link-failure!
If we UNCHECK the "Maintain connections across client requests. " setting in CFAdmin then the error goes away. The blog suggests leaving that checked, which is our preference, and using Connection Validation of "SELECT 1;". Try that...same error.
We've also tried the JDBC AutoConnect=true option. No effect.
Downloaded latest JDBC Connector and used it instead of standard CF10-MySQL connector. No effect.
Again, 99% of the site works with the exception of these two links, both of which work just fine in all our other environments. Any other ideas?
I feel like I've had a similar problem every time I upgrade CF or MySQL. Usually a change in the JDBC driver or connection string helps, which I see you already tried.
Have you checked the MySQL error log for any hints? Ours is in /var/lib/mysql (whatever your 'datadir' variable is set to) and ends with a .err extension.
Also, maybe trying some of the other JDBC connection string options for your version? I see some extended logging you can enable.
http://dev.mysql.com/doc/refman/5.1/en/connector-j-reference-configuration-properties.html
Found the issue. We are running our network on Savvis' cloud infrastructure. The Windows server instances we were using from Savvis had Trend Micro Deep Security Agent installed. This is an intrusion protection system and it was the problem. Disabling the service cleared up all communication errors. I have no clue why it was rejecting some queries that it had just accepted previously. I am just glad to (finally) put this behind me!
I cannot figure out how to access a MySQL database while running in Jenkins CloudBees. I have tried following the Dev#Cloud MySQL, but there are a lot of warnings in the console output and I have to deal with localhost access vs. sockets, which is pretty tricky to debug without a command line.
Is there a way to use the CloudBees MySQL hosting? When I try and use the cloudbees JDBC driver, I get ClassNotFound error messages.
Update: The answer below clarified that I cannot use the CloudBees driver, so I am now using the regular MySQL connector through the c3p0 connection pool. Based on comments below, I have limited the number of connections in the pool to 10.
The exact same configuration and Maven command line works when I run it from my development computer, connecting to the Cloudbees Mysql instance.
Unfortunately, I get this error when trying to connect:
Caused by: com.googlecode.flyway.core.exception.FlywayException: Unable to obtain Jdbc connection from DataSource
at com.googlecode.flyway.core.util.jdbc.JdbcUtils.openConnection(JdbcUtils.java:56)
at com.googlecode.flyway.core.Flyway.execute(Flyway.java:864)
at com.googlecode.flyway.core.Flyway.migrate(Flyway.java:591)
at com.assuredlabor.db.DatabaseMigrator.migrate(DatabaseMigrator.java:13)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeCustomInitMethod(AbstractAutowireCapableBeanFactory.java:1414)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1375)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1335)
... 62 more
Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at com.googlecode.flyway.core.util.jdbc.JdbcUtils.openConnection(JdbcUtils.java:50)
... 72 more
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
... 74 more
Any ideas would be appreciated.
You can't use CloudBees JDBC driver from outside the RUN#Cloud container, but you can use a standard MySQL JDBC driver with your RUN database using the host name and port that you can find on RUN#Cloud web console for your DB resource.
All,
I have a Hudson running fine, but I wanted to get exact similar setup in another test machine so I tried following steps:
Copied hudson_home from my current server to test server (Environment is identical to my current machine), with all jobs. Plugins and builds as well.
I restarted the Hudson and Tomcat but and its trying to access all of the config files under Hudson but its not able to fetch any data, trying to connect slaves and throwing some exceptions like this any advice is helpful
:
java.io.EOFException: unexpected stream termination
at hudson.remoting.Channel.<init>(Channel.java:284)
at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:270)
at hudson.slaves.CommandLauncher.launch(CommandLauncher.java:111)
at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:169)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
If all else fails, try using the Backup plugin to backup your Hudson configuration settings and restore them elsewhere.