If we do it the way Deepal had worked on a while ago, the downtime is VERY low. Basically, what we need to do is to mark the AxisService as "old" (or inactive) and then that immediately stops new messages from being delivered to it. Any already dispatched service is not at all affected - as the handler chain etc. is already computed and in any case we're not changing that AxisService instance. The new AxisService object representing the updated service can then be deployed by making that be what's found by service lookup. In other words, if we do this by locking AxisConfig then the downtime is basically time of object lock + copying a few pointers. Once all messages that are running "finish", the old AxisService will just get GC'ed.
Hmmm clearly there must be some bug in that logic; its too simple. Sanjiva. On Sun, Aug 30, 2009 at 1:16 PM, Afkham Azeez <afk...@gmail.com> wrote: > Simply deactivating-redeploying-activating is not the ideal solution. It > should be; > > maintenace-mode(service_foo)->redeploy(service_foo)->normal-mode(service_foo) > > In maintenance mode, a service will not accept new requests, but will > complete servicing existing requests. So, there is a difference between > deactivating a service & putting it into maintenance-mode, unless > deactivated services will complete the requests being processed. > > However, there will be a small downtime for this service. > > Azeez > > > On Sun, Aug 30, 2009 at 4:02 AM, Deepal jayasinghe <deep...@gmail.com>wrote: > >> >> > >> > >> > Then there's the question of how to do the update - ideal is to let >> > messages that are already being processed be processed by the still >> > active version and to direct new messages to the new version. I'm not >> > sure that's implementable though .. or it would require one to bring >> > that concept into dispatchers etc. to do the right thing. Ideal is for >> > it to be burnt into the AxisConfig but that's a *huge* change. >> It is doable, and in fact I have done that, but did not commit my >> changes, since it was just for fun :). >> In AxisService you have a method called activate/inactivate, when you >> inactive a service system does not take any more request to that service >> (will throw an exception saying service not found) and will process all >> the current messages. Then, you need call the deployment engine to >> update the new service (Deployment engine has a method to load a >> particular services). Then you back in business. >> >> Thanks, >> Deepal >> > > > > -- > Thanks > Afkham Azeez > > Blog: http://afkham.org > Developer Portal: http://www.wso2.org > WSAS Blog: http://wso2wsas.blogspot.com > Company: http://wso2.com > GPG Fingerprint: 643F C2AF EB78 F886 40C9 B2A2 4AE2 C887 665E 0760 > -- Sanjiva Weerawarana, Ph.D. Founder, Director & Chief Scientist; Lanka Software Foundation; http://www.opensource.lk/ Founder, Chairman & CEO; WSO2, Inc.; http://www.wso2.com/ Member; Apache Software Foundation; http://www.apache.org/ Visiting Lecturer; University of Moratuwa; http://www.cse.mrt.ac.lk/ Blog: http://sanjiva.weerawarana.org/
