Supun, What is the issue that we are trying to solve here? I am sorry I am confused :-( .
ESB (to be more specific the nhttp transport) uses a connection pool to support keep-alive, if you want each and every request going out from ESB lookup the DNS and create a new connection, you may disable keep-alive by putting a property named http.connection.disable.keepalive into the nhttp.properties file. Yet again if a DNS change has been occurred while trying to reuse an existing connection, it will fail and the connection will be reset and there is a retry on the endpoint which is configurable and will connect to the correct endpoint. I am sorry, I don't see any issue here :-( Thanks, Ruwan Supun Kamburugamuwa wrote: > Actually this is not the server side of ESB that I'm talking about. It > is the client side of the ESB. > > Anyway if we can test a scenario like this it will be great. > > >From code here is what should happen. > > We have a connection pool with host name and ip address. So even > though the DNS server is configured to point to a new IP address for a > host name, the connection pool doesn't change. For these connections > to become un-usable the back end server which hosted the services > should be shut down. Until that ESB can still send messages to the old > server because it is taking connections from a connection pool. > > When ESB creates new connections after the DNS change, it will do it > correctly. > > Thanks, > Supun.. > > On Sat, Dec 12, 2009 at 12:15 PM, Senaka Fernando <[email protected]> wrote: > >> Hi Supun, >> >> If you have configured the server to use the host name instead of the ip >> address, it should work without any issues. If you did use the ip address as >> the host name or didn't specify it, the change in ip address could cause >> some aspects not to work, such as calculated EPRs in EventBrokers. >> >> Thanks, >> Senaka. >> >> On Sat, Dec 12, 2009 at 9:35 AM, Afkham Azeez <[email protected]> wrote: >> >>> Yeah, not only for ESB, but for any generic client-server system this >>> should not cause any problems as long as the first machine is kept online >>> until all requests it received have been served. If that machine is taken >>> offline immediately, the request which were in flight and which were being >>> processed will fail. So there should be a graceful mechanism to do this, >>> like our graceful shutdown procedure. Subsequent requests should be >>> successfully forwarded to the new machine though. >>> Azeez >>> >>> On Sat, Dec 12, 2009 at 5:23 AM, Supun Kamburugamuwa <[email protected]> >>> wrote: >>> >>>> Hi, >>>> >>>> Suppose we have several back end services and ESB refer to them using >>>> a URL. These URLs are DNS resolvable URLs not IP address. Suppose we >>>> substitute a new physical machine with a different IP and configure >>>> the DNS server to point to the new IP for the same old URL. The >>>> question is what will happen? >>>> >>>> From the code it seems ESB will work correctly. I thought of bringing >>>> this question up to make sure that it will work. >>>> >>>> Thanks, >>>> Supun.. >>>> >>>> _______________________________________________ >>>> Carbon-dev mailing list >>>> [email protected] >>>> https://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev >>>> >>> >>> -- >>> -- >>> Afkham Azeez >>> [email protected] >>> WSO2 Inc. http://wso2.com >>> Blog: http://afkham.org >>> >>> _______________________________________________ >>> Carbon-dev mailing list >>> [email protected] >>> https://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev >>> >>> >> >> -- >> Senaka Fernando >> Software Engineer >> WSO2 Inc. >> E-mail: [email protected]; Mobile: +94 77 322 1818 >> >> http://www.wso2.com/ - "The Open Source SOA Company" >> >> _______________________________________________ >> Carbon-dev mailing list >> [email protected] >> https://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev >> >> >> > > _______________________________________________ > Carbon-dev mailing list > [email protected] > https://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev > > -- Ruwan Linton Technical Lead & Product Manager; WSO2 ESB; http://wso2.org/esb WSO2 Inc.; http://wso2.org email: [email protected]; cell: +94 77 341 3097 blog: http://blog.ruwan.org _______________________________________________ Carbon-dev mailing list [email protected] https://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
