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Ask the Experts Replay: HA Manager in WebSphere Application Server



IBM Ask the Experts discussion about HA Manager in WebSphere Application Server on 12 September 2013 at 11:00 AM EDT

A high availability manager provides several features that allow other product components to make themselves highly available. This webcast covers various types of questions on HA Manager in WebSphere Application Server.


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Ask the Experts session
12 September 2013 - 11:00 a.m. - 12:00 p.m. EDT

Time Questions asked
00:00 General introduction
03:17 Technical introduction
05:33 What should be the heap size of core group co-ordinator?
09:55 At times I've seen some HA-enabled JVMs take quite a long time to start up. What is the cause of this, and how can this be remedied?
12:25 CWRLS0030W message continuously logged in SystemOut. How do I resolve the issue?
21:33 I've a question in regards to HA manager recovery due to network 'instabilities' ....
27:25 How do I know when the core group co-ordinator is on a CPU-constrained system?
31:11 What are the advantages and disadvantages of disabling the HA Manager ?
34:01 How do I decide which Application Server process should be a core group co-ordinator?
35:50 What is the recommended way to disable HA?
37:08 Open lines for live question and answer period
37:13 Where is the heap size of the heap coordinator set?
37:58 CPU starvation messages on VMWARE, are these platform-specific?
39:23 Would the Node Agent be a good candidate for running the coordinator?
40:41 We have over 130 JVMs in one core group. During server startup, I often see "waiting for HA Manager to activate Recovery processs". Can this be tweaked somehow?
44:14 There are two tuning parameters available for the core group, to enable protocols. Why are those protocols not enabled by default?
46:35 What is the recommended maximum JVMs for a single core group?
49:00 If you don't have a preferred coordinator set, what happens?
49:44 I get JVM errors, which are continuously spooled unti I kill the JVM with the problem. What causes that behavior?
54:12 Is there any downside to having a large number of coordinators? And can you explain more about setting the transport memory size?
56:45 Is there a way to track how much transport memory is being used?
58:47 How to add one more coordinator?
59:57 Is Core Group Coordinator also one of the application JVM clones in the cluster or is this a separate JVM?
60:43 When you say meme\bers in the core group, what are these members? JVMs?
61:04 If I have only Web Services in the Application JVM Clones, and the EJBs are all accessed locally, can I disable HA safely?
62:17 What is core group?
62:36 What is the fix, if a member is not able to join a coregroup, apart from moving all members to a different coregroup?
63:15 Can core group bridge connect the core groups in different cells?
64:00 Why does there have to be a nodeagent or dmgr in every core group?
64:45 How does the authentication happen when two core groups across different cells needs to be linked?
65:20 Can we disbale HA manager, if we are not using memory-to-memory replication?
66:40 How do you know at any one time which is the coordinator?
67:17 Where to set the heap size for coregroup?
68:01 We don't use any of the features like Memory-to-memory replication or Tran log on shared storage or On-demand routing. Then do you think is it better to diable HA manager?
61:08 We have 193 members. what is the recommende max memory?
69:49 I have read somewhere that you cannot have more than 50 JVMs per coregroup. Is that true?
70:43 If we can have more than 50 JVMs in a single coregroup, do we need to have multiple coordinators?
71:43 Is there a webcast that explains the HA Manager and how it works?
72:34 What is the function of the core group services Thread Pool properties?
73:10 For "checking the view change msg in the sysout logs", which log? SystemOUt, dmgr,or JVM?
74:00 IBM recommends setting the preferred coordinator property. Where can we set this property in a JVM?
74:59 Is there any policy for setting preferred coordinator?
75:40 If I have a preferred coordinator and that is taken down, presumably coordinator swaps to a different JVM. When I bring the preferred one back up, does it become the coordinator again (ie swaps back)?
76:13 In case we have no preferred server defined in the coregroup, how and which server would be chosen to perform the operation?
76:47 Once I have dedicated a jvm as preferred coordinator, do I need to make any configuration changes related to coregroup services for other JVMs?
77:09 Where can you disable HA Manager setting?
77:49 In logs I see view size is 27 (AV=28, CD=29, CN=29, DF=31). Could you pls elaborate what each value is meant (AV, CD CN DF)?
78:39 What has to be considered for electing preferred coordinator? Such as load on JVM, etc. Can you explain more?
80:53 Closing remarks
82:59 End of Call

Panel of Experts:
Kumaran Nathan WebSphere Application Server Level 2 Support
Krishna Jaladhi WebSphere Application Server Level 2 Support
Salnave (Sal) Saint-Fort WebSphere Application Server Level 2 Support
Hobert Bush III WebSphere Application Server Level 2 Support
David Follis IBM WebSphere Application Server Development



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Related information

WebSphere Support Technical Exchange

Document information

More support for: WebSphere Application Server
High Availability (HA)

Software version: 7.0, 8.0, 8.5, 8.5.5

Operating system(s): AIX, HP-UX, Linux, Solaris, Windows

Reference #: 7039197

Modified date: 13 September 2013

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