<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:16px"><div id="yiv7489189790"><div id="yui_3_16_0_1_1446977812562_8300"><div style="color:#000;background-color:#fff;font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:16px;" id="yui_3_16_0_1_1446977812562_8299"><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835">Thank You Michael,</div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835"><br></div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835" dir="ltr">In fact I spent some more time looking at documentions and indeed Pacemaker is only used for resource control and management. To have my HA solution I will need to use Corosync directly as well. The OpenAIS API is pretty well described and I am starting to understand what must be done (basically link my binaries with corosync and use the messages and other APIs to have a accurate states of remote objects/services). </div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835" dir="ltr"><br></div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835" dir="ltr">As for the Virtual IP I believe it makes more sense to use it in case of Active/Standby services. In my case B services being both active i would need to implement the load balancing within service A (using openAIS/Corosync API to be updated of service B state changes and how to reach the service B I have elected through round robin). For those specific components I don't foreseen the need of Virtual IP. However I may use VIP for my service A and other components!</div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835" dir="ltr"><br></div><div id="yiv7489189790yui_3_16_0_1_1446977812562_6835" dir="ltr">Thanks,</div> <br clear="none"><div class="yiv7489189790qtdSeparateBR" id="yui_3_16_0_1_1446977812562_8301"><br clear="none"><br clear="none"></div><div class="yiv7489189790yqt4285102557" id="yiv7489189790yqt27760"></div></div></div></div><div class=".yiv7489189790yahoo_quoted"> <div style="font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:16px;"> <div style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div dir="ltr"> <font size="2" face="Arial"> Le Dimanche 8 novembre 2015 16h24, Michael Schwartzkopff <ms@sys4.de> a écrit :<br clear="none"> </font> </div> <br clear="none"><br clear="none"> <div class="yiv7489189790y_msg_container">Am Samstag, 7. November 2015, 09:40:47 schrieb didier tanti:<br clear="none">> Hello, i am new to Pacemaker and have a question concerning how to have my<br clear="none">> cluster services aware of the state and location of the other services in<br clear="none">> the cluster. Example:<br clear="none">> Service A is running on Host XService B1 is running on Host XService B2 is<br clear="none">> running on Host Y Which API would allow my Service A to send IPC messages<br clear="none">> to services B1 and B2 in a round robin manner?(for example how Service A<br clear="none">> would be aware of which B is up and active (B1, B2 or both), and how A<br clear="none">> would even be able to know on which host B1 or B2 is running?) It looks<br clear="none">> very basic but i cannot find information on this on clusterlabs.org Is<br clear="none">> there basic tutorial that would explain how to achieve this ? (I guess i<br clear="none">> would need to link my service binaries with some pacemaker /corosync libs<br clear="none">> and use some API ?) Thanks for helping out,<br clear="none"><br clear="none">Hi,<br clear="none"><br clear="none">this task is beyond the ability of pacemaker. Your application has to know how <br clear="none">to handle that.<br clear="none"><br clear="none">Best solution would be to use virtual IP addresses for services B1 and B2. <br clear="none">make sure that the IP addresses run together with the services. Now you <br clear="none">service A only has to talk to the IP addresses, no matter on which host they <div class="yiv7489189790yqt8977291502" id="yiv7489189790yqtfd90513"><br clear="none">run.</div><br clear="none"><br clear="none">pacemaker could take care that they run on different hosts is possible.<br clear="none"><br clear="none">Mit freundlichen Grüßen,<br clear="none"><br clear="none">Michael Schwartzkopff<br clear="none"><br clear="none">-- <br clear="none">[*] sys4 AG<br clear="none"><br clear="none"><a rel="nofollow" shape="rect" target="_blank" href="http://sys4.de%2C/">http://sys4.de, </a>+49 (89) 30 90 46 64, +49 (162) 165 0044<br clear="none">Franziskanerstraße 15, 81669 München<br clear="none"><br clear="none">Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263<br clear="none">Vorstand: Patrick Ben Koetter, Marc Schiffbauer<br clear="none">Aufsichtsratsvorsitzender: Florian Kirstein<br clear="none"><br clear="none"></div> </div> </div> </div></div></body></html>