Alter channel page https://www.ibm.com/support/knowledgecenter/SSFKSJ_7.5.0/com.ibm.mq.ref.adm.doc/q085170_.htm shows that I can use Disconnect interval (DISCINT) in server connection channel alter command, however I get error message which claims that it can only be used for server or sender channel types, but not for server connection channel types.
Maybe MQ command level is too low for DISCINT attribute? How can I check that?
Operating System is Linux for that particular workgroup server...
This knowledge center page for MQ v 7.0.1 indicates that alter chl DISCINT is only valid on zOS.
Also, this page says: This attribute is valid for channel types Server connection (z/OS® only)
Maybe you are using an older version of MQ? There are many different ways to check your MQ version - from the command line try dspmqver.
Related
I work on a Java application which uses com.ibm.mqjms version 6.0.2.2. I just upgraded to com.ibm.mq.allclient version 9.3.1.0.
After the upgrade, all attempts to put a message on the queue results the following error :
com.ibm.mq.MQException: MQJE001: Completion Code '2', Reason '2035'.
The error message given by queue manager is :
AMQ9557E: Queue Manager User ID initialization failed for '[username]'.
EXPLANATION:
The call to initialize the User ID '[username]' failed with CompCode 2 and Reason
2035. If an MQCSP block was used, the User ID in the MQCSP block was ''. If a
userID flow was used, the User ID in the UID header was '' and any CHLAUTH
rules applied prior to user adoption were evaluated case-sensitively against
this value.
ACTION:
Correct the error and try again.
I've tried to add the following in the java application to disable MQCSP, but this did not help.
Hashtable props = new Hashtable();
props.put(MQConstants.USER_ID_PROPERTY, false);
props.put(MQConstants.PASSWORD_PROPERTY, false);
props.put(MQConstants.USE_MQCSP_AUTHENTICATION_PROPERTY, Boolean.FALSE);
this.queueManager = new MQQueueManager(getManager(), props);
What can I do to troubleshoot this issue? Since the issue only exists with the more recent version of the MQ java client, I'd think the issue is caused by the client?
AMQERR01.LOG
2023-01-03 13:28:41 - Process(2838.71) User(mqm) Program(amqrmppa)
Host([HOSTNAME]) Installation(Installation1)
VRMF(9.2.5.0) QMgr(TSTMQ01)
Time(2023-01-03T12:28:41.959Z)
ArithInsert1(2) ArithInsert2(2035)
CommentInsert1([USERNAME])
AMQ9557E: Queue Manager User ID initialization failed for '[USERNAME]'.
EXPLANATION:
The call to initialize the User ID '[USERNAME]' failed with CompCode 2 and Reason
2035. If an MQCSP block was used, the User ID in the MQCSP block was ''. If a
userID flow was used, the User ID in the UID header was '' and any CHLAUTH
rules applied prior to user adoption were evaluated case-sensitively against
this value.
ACTION:
Correct the error and try again.
To get the prior v6 behavior set the java system property user.name to an empty value, for example on the command line add this:
-Duser.name=
or in your program add this:
System.setProperty("user.name", "")
Background:
The IBM MQ classes for Java and IBM MQ classes for JMS are the only libraries where IBM allows you to set the username that is passed to MQ in the protocol field called RemoteUserIdentifier. This has been in place since the Java and JMS classes were released. IBM has stated this is because a java app does not have direct access to the user the process runs under only the java system property user.name which will be filled in by the JVM with a username but can be overridden as a java system property. On the other hand C, C++, .NET and XMS MQ client APIs all pass the user that the process is running as in the RemoteUserIdentifier field and you cannot override this and specify an arbitrary value.
Java and JMS also were the only APIs to allow you to specify a password value and this would be sent to the queue manager in the RemotePassword field. The RemoteUserIdentifier/RemotePassword fields are part of the MQCD (MQ channel defination) that the client sends to the queue manager when connecting.
Prior to v8 the queue manager had no built in functionality to authenticate any username or password value that was provided, you would need a security exit to get any additional validation. If you configure your MQ SVRCONN channel to allow connections as any ID with no protection (Blank MCAUSER and no security exits or SSLCIPH/SSLPEER to restrict access, then anyone can write a simple Java or JMS MQ application to assert any user value and get access to what that user would have access to on MQ, even without java someone with admin rights on there own desktop or server can just create a local user with the right name and run a C program and get similar access. It is never a good idea to accept an arbitrary asserted ID without some form of validation.
Prior to CHLAUTH which was added in MQ v7.1 the default configuration of a new queue manger was to allow the asserted id to be administrative unless you protected against this, this could be as simple as passing the value "mqm" to a linux queue manager or simply passing a blank value, if the MCAUSER was also blank on the SVRCONN channel the channel would run under the authority of the process running the listener which would be the "mqm" user.
With 7.1 and higher a new queue manager is created by default with CHLAUTH(ENABLED) and a few default CHLAUTH rules, one restricts access to all channels that start with "SYSTEM" and another denies connections to SVRCONN channels from any user MQ determines has administrative authority. Note that if a queue manager was created at a version prior to 7.1, then later upgraded to 7.1 or higher the default is to leave CHLAUTH(DISABLED), so unless you alter it to set it to ENABLED at some point you do not have these protections.
On the Java/JMS client side prior to 7.1, if you did not set the username a blank value would be passed in the RemoteUserIdentifier, after 7.1, if you do not set the username then the client defaults to sending the value of the java system property user.name, if you do set the username it is still sent in favor to the user.name value.
Since MQ v7.0 non-java APIs have had the ability to send an additional structure to the queue manager during the channel connection called the MQCSP which has fields for a username and password and AuthenticationType, but similar to what I said about RemoteUserIdentifier/RemotePassword prior to v8 there was no built in functionality to actually authenticate or do anything with these values, you would need to use a security exit to get this functionality. Note the MQCSP.AuthenticationType field has two possible values, MQCSP_AUTH_NONE (indicating that you do not want authentication performed) or MQCSP_AUTH_USER_ID_AND_PWD (indicate that you want authentication performed).
Since MQ v8.0 the Java and JMS APIs now also have the ability to send the username and password values in the MQCSP instead of the MQCD RemoteUserIdentifier/RemotePassword fields, but for all versions of MQ v8.0, MQ v9.0.0.x (LTS) and 9.0.x (CD), 9.1.0.x (LTS), and 9.1.x (CD) the default is to send the username and password in compatibility mode still using the RemoteUserIdentifier/RemotePassword fields of the MQCD. To have Java and JMS use the MQCSP, you have to specifically set a property. When the specified username and password is sent in the MQCSP the RemoteUserIdentifier is filled in with the java system property user.name by default. Note that in 9.3 it seems the default is now send the username and password in the MQCSP structure instead of in compatibility mode.
At v8.0 and later the queue manager now has the feature called CONNAUTH which can authenticate a username and password that is sent via either MQCSP or RemoteUserIdentifier/RemotePassword. There are various configuration options around how this is configured, but by default at v8 or later if a username and password (note the password could be empty in this case) are sent to the queue manager and MQCSP.AuthenticationType is set to MQCSP_AUTH_USER_ID_AND_PWD, they will be validated to be correct, and if an administrative user is sent to the queue manager it must provide a password and be correct.
For Java/JMS APIs, if no MQCSP is sent by the client but RemoteUserIdentifier and RemotePassword both have a value, the queue manager will build a MQCSP with MQCSP.AuthenticationType set to MQCSP_AUTH_USER_ID_AND_PWD and validate it the same way, note in this case if RemotePassword is empty a MQCSP structure is not built.
Conclusion:
Based on the description of how you state that the Java app with v6 jars is functioning, this means that anyone that has access to connect the MQ listener port of your queue manager can specify any username that has access to MQ including the queue manager admin user. It would be much better to send a username and password that will be validated, or use client TLS certificates to assert identity (When combined with setting the channels SSLPEER and a MCAUSER (or a CHLAUTH SSLPEERMAP rule) you can greatly restrict who can connect to your channel, and you eliminate the ability for them to assert any arbitrary username.
I have a Spring Boot app using JMSListener + IBMConnectionFactory + CCDT for connecting an IBM MQ Cluster.
A set the following connection properties:
- url pointing to a generated ccdt file
- username (password not required, since test environment)
- queuemanager name is NOT defined - since it's the cluster's task to decide, and a few google results, including several stackoverflow ones indicate that in my case qmgr must be set to empty string.
When my Spring Boot JMSListener tries to connect to the queue, the following MQRC_UNKNOWN_ALIAS_BASE_Q error occurs:
2019-01-29 11:05:00.329 WARN [thread:DefaultMessageListenerContainer-44][class:org.springframework.jms.listener.DefaultMessageListenerContainer:892] - Setup of JMS message listener invoker failed for destination 'MY.Q.ALIAS' - trying to recover. Cause: JMSWMQ2008: Failed to open MQ queue 'MY.Q.ALIAS'.; nested exception is com.ibm.mq.MQException: JMSCMQ0001: IBM MQ call failed with compcode '2' ('MQCC_FAILED') reason '2082' ('MQRC_UNKNOWN_ALIAS_BASE_Q').
com.ibm.msg.client.jms.DetailedInvalidDestinationException: JMSWMQ2008: Failed to open MQ queue 'MY.Q.ALIAS'.
at com.ibm.msg.client.wmq.common.internal.Reason.reasonToException(Reason.java:513)
at com.ibm.msg.client.wmq.common.internal.Reason.createException(Reason.java:215)
In the MQ error log I see the following:
01/29/2019 03:08:05 PM - Process(27185.478) User(mqm) Program(amqrmppa)
Host(myhost) Installation(Installation1)
VRMF(9.0.0.5) QMgr(MyQMGR)
AMQ9999: Channel 'MyCHL' to host 'MyIP' ended abnormally.
EXPLANATION:
The channel program running under process ID 27185 for channel 'MyCHL'
ended abnormally. The host name is 'MyIP'; in some cases the host name
cannot be determined and so is shown as '????'.
ACTION:
Look at previous error messages for the channel program in the error logs to
determine the cause of the failure. Note that this message can be excluded
completely or suppressed by tuning the "ExcludeMessage" or "SuppressMessage"
attributes under the "QMErrorLog" stanza in qm.ini. Further information can be
found in the System Administration Guide.
----- amqrmrsa.c : 938 --------------------------------------------------------
01/29/2019 03:15:14 PM - Process(27185.498) User(mqm) Program(amqrmppa)
Host(myhost) Installation(Installation1)
VRMF(9.0.0.5) QMgr(MyQMGR)
AMQ9209: Connection to host 'MyIP' for channel 'MyCHL' closed.
EXPLANATION:
An error occurred receiving data from 'MyIP' over TCP/IP. The connection
to the remote host has unexpectedly terminated.
The channel name is 'MyCHL'; in some cases it cannot be determined and so
is shown as '????'.
ACTION:
Tell the systems administrator.
Since the MQ error log contains QMgr(MyQMGR), which MyQMGR value I did not set in the connection properties, I assume the routing seems to be fine: the MQ Cluster figured out a qmgr to use.
The alias exists and points to an existing q. Bot the target q and the alias are added to the cluster via the CLUSTER(clustname) command.
What can be wrong?
Short Answer
MQ Clustering is not used for a consumer application to find a queue to GET messages from.
MQ Clustering is used when a producer application PUTs messages to direct them to a destination.
Further reading
Clustering is used when messages are being sent to help provide load balancing to multiple instances of a clustered queue. In some cases people use this for hot/cold failover by having two instances of a queue and keeping only one PUT(ENABLED).
If an application is a producer that is putting messages to a clustered queue, it only needs to be connected to a queue manager in the cluster and have permissions to put to that clustered queue. MQ based on a number of different things will handle where to send that message.
Prior to v7.1 there was only two ways to provide access to remote clustered queues:
Using a QALIAS:
Define a local QALIAS which has a TARGET set to the clustered queue name
Note this QALIAS does not itself need to be clustered.
Grant permission to put to the local QALIAS.
Provide permissions to PUT to the SYSTEM.CLUSTER.TRANSMIT.QUEUE.
The first option allows for granting granular access to an application for specific clustered queues in the cluster. The second option allows for the application to put to any clustered queue in the cluster or any queue on any clustered queue manager in the cluster.
At 7.1 IBM added a new optional behavior, this was provided with the setting ClusterQueueAccessControl=RQMName in the Security stanza of the qm.ini. If this is enabled (it is not the default), then you can actually provide permission for the app to PUT to the remote clustered queues directly without the need for a local QALIAS.
What clustering is not for is consuming applications such as your example of a JMSListener.
An application that will consume from any QLOCAL (clustered or not) must be connected to the queue manager where the QLOCAL is defined.
If you have a situation where there are multiple instances of a clustered QLOCAL that are PUT(ENABLED), you would need to ensure you have consumers connected directly to each queue managers that an instance is hosted on.
Based on your comment you have a CCDT with an entry such as:
CHANNEL('MyCHL') CHLTYPE(CLNTCONN) QMNAME('MyQMGR') CONNAME('node1url(port1),node2url(port2)')
If there are two different queue managers with different queue manager names listening on node1url(port1) and node2url(port2), then you have different ways to accomplish this from the app side.
When you specify the QMNAME to connect to the app will expect the name to match the queue manager you connect to unless it meets one of the following:
If you specify *MyQMGR it will find the channel or channels with QMNAME('MyQMGR') and pick one and connect and will not enforce that the remote queue manager name must match.
If in your CCDT you have QNAME(''), it is set to NULL, then in your app you can specify a empty queue manager name or only a space and it will find this entry in the CCDT and will not enforce that the remote queue manager name must match.
In your app you specify the queue manager name as *, MQ will use any channel in the CCDT and will not enforce that the remote queue manager name must match.
One limitation of CCDT is that channel name must be unique in the CCDT. Even if the QMNAME is different you can't have a second entry with the same channel name.
When you connect you are hitting the entry with two CONNAME's and getting connected to the first IP(port), you would only get to the second IP(port) if at connect time the first is not available, MQ will try the second, or if you are connected and have RECONNECT enabled and then the first goes down MQ will try to connect to the first then second.
If you want to have both clustered queue PUT(ENABLED) to receive traffic then you want to be able to specifically connect to each of the two queue managers to read those queues.
I would suggest you add a new channel on each queue manager that has a different QM specific name that is also different from the existing name, something like this:
CHANNEL('MyCHL1') CHLTYPE(CLNTCONN) QMNAME('MyQMGR1') CONNAME('node1url(port1)')
CHANNEL('MyCHL2') CHLTYPE(CLNTCONN) QMNAME('MyQMGR2') CONNAME('node2url(port2)')
This would be in addition to the existing entry.
For your putting components you can continue to use the channel that can connect to either queue manager.
For your getting components you can configure at least two of them, one to connect to each queue manager using the new queue manager specific CCDT entries, this way both queues are being consumed.
we have facing error, application unable to connect to queue manager,with reason
code mqrc 2538,
webspher MQ version v7.0.1.2.
operating system "Solaris".
I have started the listener manually through
runmqlsr -m qmname -t tcp -p port
after i have checked status of listener through command,
display lsstatus(listener name)
"listener is available but when I try to display the status of this listener it is showing MQ object not found."
we have checked error logs but there is no information for related client fails we have started listener manually, listener information only available in error logs.
Also we have checked "/var/mqm/error" we found the FDC files "probe ID: XY132002" we have contact with sysadmin they mount the disk space.
After mounting /var/mqm/ disc space still we are facing the same issue.
i have already given "start lstr(lstr name)" in script mode, but i its accepting the request, while I try to display the status of this listener it is showing MQ object not found."
i have checked qmgr error logs and fdc error logs"
can you please find the below errors written in /var/mqm/errors/AMQERR01.LOG
Explanation: 1. An attempt hasbeen made to run the brker(SFMSICREQMGR) but the brker has ended for reason '6119:xecF_E_UNEXPECTED_SYSTEM_RC'.
error: AMQ6119:An internal WebSphere MQ error has occured(failed to get memory segment:shmget(0x00000000, 16384) [rc =1 errno=28] no space left on device.
++below error written in queue manger level error:++
AMQ5008: An essential websphere MQ process 10063 (amqfgpub) cannot be found is assumed to be terminated.
these are errors written in queue manager level error logs and system level error logs:
we have added below values
process.max-file-descriptor=(basic,10000,deny)
project.max-sem-ids=(priv,1024,deny)
project.max-shm-ids=(priv,1024,deny)
project.max-shm-memory=(priv,4294967296,deny)
after adding this parameters we restarted the queue manager's,
we have four queue managers in server, three queue managers and listeners are in running state, fourth queue manager facing same error.
we have stopped one queue manager and we have run the fourth queue manager,the fourth queue manager is running and listener also in running state.
one queue manager is not allowing to start. we are facing same error for this queue manager.
All queue managers and listeners running fine.
we have created local queue,
queue name(error_local_queue).but while application tried get msg from this queue his getting error
Mqrc 2033.
Kindly help for this issue
thank you so much to all issue got resolved.
If you start a listener using the following command (as per your question):-
runmqlsr -m qmname -t tcp -p port
Then you have not specified a name for the listener anywhere (because this command does not have that capability).
It will however still show up in a DISPLAY LSSTATUS command with a system generated name. If you use the following command:-
DISPLAY LSSTATUS(*)
that will show all running listeners, and you will see that there is one with a name something like SYSTEM.LISTENER.TCP.1 which is your runmqlsr one.
Alternatively, if you want to give your listener a specific name, then you must define a listener as follows (replacing nnnn with your port number):-
DEFINE LISTENER(TCP.LSTR) TRPTYPE(TCP) CONTROL(QMGR) PORT(nnnn)
Then you are able to start it as follows:-
START LISTENER(TCP.LSTR)
and show it's status as follows:-
DISPLAY LSSTATUS(TCP.LSTR) ALL
N.B. I used the name TCP.LSTR but you may choose any name you wish.
The errors you mention at the end of your question are unrelated to listeners. Please open a separate question for those.
MQ v7.0 has been out of support since September 30th 2015.
The errors you found indicate the queue manager is short on shared memory, this could cause the entire queue manager to have issues including your listener. The current values along with IBM's recommendations can by found using the mqconfig script.
MQ v7.0 did not come with the mqconfig script. Download the script and verify which kernel settings are not correct, the download site is "How to configure UNIX and Linux systems for IBM MQ".
You can find more information on setting these in the IBM MQ v7 Knowledge Center page "Resource limit configuration".
The values in the Knowledge center are recommended values for a average server with a couple of queue managers and should be treated as a minimum value. If you can't run 4 queue managers then I would suggest going to higher values. I would start with setting max-sem-ids and max-shm-ids to 10240 and see if that solves it, if not then attempt to add 50% to the max-shm-memory value.
I am trying to put a message into Websphere MQ queue from an Orchestration which is deployed on Cast Iron Live. I have used secure connector since the orchestation is deployed on Cast Iron. When I am trying to execute the flow, it fails and the message is not placed in MQ queue. The below are the errors:
Error while trying to call remote operation execute on Secure Connector for activity
com.approuter.module.mq.activity.MqPut and Secure Connector LocalSecureConnector,
error is Unable to put message on queue null. MQ returned error code 2538.
Unable to put message on queue null. MQ returned error code 2538.
Fault Name : Mq.Put.OperationActivityId : 163
Message: Unable to put message on queue null. MQ returned error code 2538.
Activity Name:Put MessageFault Time: 2015-07-15T05:40:29.711Z
Can someone please help me resolve this. Please let me know if any further details are required.
Here are the details:
Cast Iron flow is deployed on Cast Iron Cloud i.e Cast Iron Live
MQ is running on-premise
The port I am trying to connect is 1414.
Have a secure connector running on the machine where MQ is installed.
MQ version is 8.
In Cast Iron flow, I am using an MQ connector, by giving the hostname where MQ is running, port: 1414, Channel Name : SYSTEM.DEF.SVRCONN and username as mqm. Tired using my log on username, by adding it to mqm group. But this also dosent seem to work.
The return code is instructive:
2538 0x000009ea MQRC_HOST_NOT_AVAILABLE
This indicates that Cast Iron is attempting to contact MQ using a client connection and not finding a listener at the host/port that it is using.
There are a couple of possibilities here but not enough info to say which it might be. I'll explain and provide some diagnostics you can try.
The 2538 indicates an attempt to contact the QMgr has failed. This might be that, for example, the QMgr isn't listening on the configured port (1414) or that the MQ listener is not running.
The error code says the queue name is "null". The question doesn't specify which queue name the connector is configured with but presumably it's been configured with some queue name. This error code suggests the Secure Connector on the MQ server side doesn't have its configuration installed.
The Cast Iron docs advise connecting with an ID in the mqm group but do not mention that on any MQ version 7.1 or higher this is guaranteed to fail unless special provisions are made to allow the admin connection. It may be that it's actually failing for an authorization error and the connector not reporting the correct error.
If it is as simple as the listener not running, that's easy enough to fix. Just start it and make sure it's on 1414 as expected.
Next, ensure that the Secure Connector has the configuration that was created using the Cast Iron admin panel. You need to understand why the error code says the queue name is null.
Now enable Authorization Events and Channel Events in the QMgr and try to connect again. The connector on the MQ server should connect when started and if successful you can see this by looking at the MQ channel status. However, if unsuccessful, you can tell by looking at the event messages or the MQ error logs. Both of these will show authorization failures and connection attempts, if the connection has made it that far.
The reason I'm expecting 2035 Authorization Error failures is that any QMgr from v7.1 and up will by default allow an administrative connection on any channel. This is configured in the default set of CHLAUTH rules. The intent is that the MQ admin would have to explicitly provision admin access by adding one or more new CHLAUTH rules.
For reasons of security SYSTEM.DEF.* and SYSTEM.AUTO.* channels should never be used for legitimate connections. The Best Practice is to define a new SVRCONN, for example one named CAST.IRON.SVRCONN and then define a CHLAUTH rule to allow the administrative connection.
For example:
DEFINE CHL(CAST.IRON.SVRCONN) CHLTYPE(SVRCONN) TRPTYPE(TCP) REPLACE
SET CHLAUTH('CAST.IRON.SVRCONN') TYPE(ADDRESSMAP) +
ADDRESS('127.0.0.1') +
USERSRC(MAP) MCAUSER('mqm') +
ACTION(REPLACE)
SET CHLAUTH('CAST.IRON.SVRCONN') TYPE(BLOCKUSER) +
USERLIST('*NOBODY') +
WARN(NO) ACTION(REPLACE)
The first statement defines the new channel.
The next one allows the connections from 127.0.0.1 which is where the Secure Connector lives. (Presumably you installed the internal Secure Connection on the same server as MQ, yes?) Ideally the connector would use TLS on the channel and instead of IP filtering the CHLAUTH rule would filter based on the certificate Distinguished Name. This rule is not nearly so slective and allows anyone on the local host to be an MQ administrator by using this channel.
The last statement overrides the default CHLAUTH rule which blocks *MQADMIN with a new rule that blocks *NOBODY but just for that channel.
I try to install WebSphere MQ v8 on Centos 7... I did have no problem instaling the server and test it. When I try to configure client every is OK until I try to put a message at queue with the following command: ./amqsputc queue manager. Here part of the log file.
-------------------------------------------------------------------------------
08/01/15 13:16:17 - Process(37991.4) User(mqm) Program(amqrmppa)
Host(localhost.localdomain) Installation(Installation1)
VRMF(8.0.0.0) QMgr(my.manager)
AMQ9776: Channel was blocked by userid
EXPLANATION: The inbound channel 'CANAL1' was blocked from address
'127.0.0.1' because the active values of the channel were mapped to a
userid which should be blocked. The active values of the channel were
'MCAUSER(mqm) CLNTUSER(mqm) ADDRESS(localhost)'. ACTION: Contact the
systems administrator, who should examine the channel authentication
records to ensure that the correct settings have been configured. The
ALTER QMGR CHLAUTH switch is used to control whether channel
authentication records are used. The command DISPLAY CHLAUTH can be
used to query the channel authentication records.
----- cmqxrmsa.c : 1257 -------------------------------------------------------
08/01/15 13:16:17 - Process(37991.4) User(mqm) Program(amqrmppa)
Host(localhost.localdomain) Installation(Installation1)
VRMF(8.0.0.0) QMgr(my.manager)
AMQ9999: Channel 'CANAL1' to host '127.0.0.1' ended abnormally.
EXPLANATION: The channel program running under process ID 37991 for
channel 'CANAL1' ended abnormally. The host name is '127.0.0.1'; in
some cases the host name cannot be determined and so is shown as
'????'. ACTION: Look at previous error messages for the channel
program in the error logs to determine the cause of the failure. Note
that this message can be excluded completely or suppressed by tuning
the "ExcludeMessage" or "SuppressMessage" attributes under the
"QMErrorLog" stanza in qm.ini. Further information can be found in the
System Administration Guide.
----- amqrmrsa.c : 925 --------------------------------------------------------
I appreciate all the help you can give me, thanks in advance.
It is very easy to troubleshoot the reasons why you have been blocked by a CHLAUTH rule. There is a blog post on it, I'm being blocked by CHLAUTH - how can I work out why?
However, I can tell you from here exactly which rule is blocking you, it is the default rule which bans remote privileged access, i.e. mqm access from client connections. If you want to have access without being privileged, read A non-privileged MQ administrator, and alternatively if you do want to allow the risky remote access from privileged users, read CHLAUTH - Allow some privileged admins
It's worth noting MQ v8 doesn't support CentOS at all, and hasn't declared support for RHEL 7 either.
http://www-969.ibm.com/software/reports/compatibility/clarity-reports/report/html/softwareReqsForProduct?deliverableId=1350550241693&osPlatform=Linux
At time of writing MQ v8 supports the following Linux distros:
Asianux 3.0
RHEL 6
SLES 11
Ubuntu 12.04
That said, the error 'AMQ9776: Channel was blocked by userid' you pasted above show that your client is failing the channel authentication checks.
You can check this by disabling channel authentication via the following MQSC command:
'ALTER QMGR CHLAUTH(DISABLED)'
There's a good article on developerworks that explains how to work out why your connection attempt was blocked you can look at here:
https://www.ibm.com/developerworks/community/blogs/aimsupport/entry/blocked_by_chlauth_why?lang=en