Can you suggest what tables to look at? From: Imesh Gunaratne [mailto:im...@apache.org] Sent: 07 May 2015 18:00 To: dev Subject: Re: Clustered deployments of Stratos
Hi Shaheed, Thanks for the clarification! May be the problem is with the MySQL active-passive configuration. I understand that you are switching the same OpenStack volume from active node to the passive node (when the passive node becomes active) therefore technically it should work. May be we need to investigate this problem further by analysing whether data is persisted properly in the active node before the passive node becomes active. Thanks On Tue, May 5, 2015 at 4:22 PM, Shaheedur Haque (shahhaqu) <shahh...@cisco.com<mailto:shahh...@cisco.com>> wrote: The data is not synchronised between the active and passive nodes. For clarity, this is the HA model we had, much as described in the blog: • 2 nodes, with Pacemaker in active-passive mode. • Under Pacemaker control: o We run MySQL in active-passive mode, using a single OpenStack volume which we attach/reattach as the active role moves around nodes. o As the Pacemaker moves the volume, and thus MySQL around on node failures, ActiveMQ and Stratos are moved around too. o Thus, everything operates in active-passive mode. Even in this model, as the active Stratos 4.0 is moved around (i.e. the Stratos JVM on the old active node has gone with the node, and Pacemaker starts up a new Stratos JVM on what used to be the passive node), we found that the Cartridge Definition objects were found to be missing and, as a clumsy workaround [1], we had to replay the stored copied of them into Stratos using the REST API. With Stratos 4.1, using the new object names , early indications are Deployment Policies and Application Deployment policies are lost as the active fails over to the passive. If anything, these objects are more likely to hit the problems of [1], since Stratos 4.1 expects these to be tweaked on the fly (min/max etc). Thanks, Shaheed [1] Clearly, this loses any changes that were not in the stored copies. From: Imesh Gunaratne [mailto:im...@apache.org<mailto:im...@apache.org>] Sent: 03 May 2015 06:43 To: dev@stratos.apache.org<mailto:dev@stratos.apache.org> Subject: Re: Clustered deployments of Stratos Hi Shaheed, Thanks for taking time to test this! Just to clarify the exact problem, do you mean that data is not synchronized between the active and passive nodes or they are not persisted in the active node? Thanks On Sunday, May 3, 2015, Shaheedur Haque (shahhaqu) <shahh...@cisco.com<mailto:shahh...@cisco.com>> wrote: I have been looking into our use of Linux HA to setup an Active-Passive configuration. Testing indicates that in 4.1 (beta1), several objects seem not to be persisted properly. This includes at least: - Cartridges - Deployment policies Am I missing something? Is it safe to workaround this by replaying those objects? ________________________________ From: Imesh Gunaratne [im...@apache.org] Sent: 23 April 2015 10:47 To: dev Subject: Re: Clustered deployments of Stratos Hi Shaheed, Currently N-way clustering is still not possible with CC, AS & SM. We completed the initial phase of this feature however it was not completed. You could refer mail thread "[Discuss] Clustering Feature Implementation for 4.1.0-Alpha Release" for details. However at present [1] is valid. We could use Linux HA and deploy CC, AS and SM in Active-Passive mode. Thanks On Thu, Apr 23, 2015 at 2:41 PM, Shaheedur Haque (shahhaqu) <shahh...@cisco.com<mailto:shahh...@cisco.com>> wrote: Hi, We currently try to achieve HA with Stratos using something so unpleasant that I won’t even describe it here ☺. It has been suggested that Stratos has, for a while now, supported a clustered mode of deployment where, given N servers: • The SM, AS and MB operate in a N-way clustered mode • The CEP operates in a N-way loadsharing mode • The Cartridge Agents can react to a failure in one of the N CEPs by failing over to one of the other N-1 remaining servers In looking for documentation on how to set this up, I came across these two write-ups [1] and [2]. Questions: • Both these documents mention only using N=2. Is that still correct? • [1] Seems recently written, and [2] is a little older but not much. Are both documents still regarded as current? Also, I’d love to hear any other experiences people have of running configurations like this. Thanks, Shaheed [1] https://cwiki.apache.org/confluence/display/STRATOS/4.1.0+Configuring+HA+Using+Pacemaker+and+Heartbeat [2] http://blog.lasindu.com/2014/08/wso2-private-paas-supporting.html -- Imesh Gunaratne Technical Lead, WSO2 Committer & PMC Member, Apache Stratos -- Imesh Gunaratne Senior Technical Lead, WSO2 Committer & PMC Member, Apache Stratos -- Imesh Gunaratne Senior Technical Lead, WSO2 Committer & PMC Member, Apache Stratos
