Hi Flavio, Thank you for the information.
So how do you handle than the following scenario? You have 5 servers and temporary network segmentation, where server 1 and 2 cannot talk to 3,4 and 5. Will server 1 and 2 do a new leader election for their partition, as well server 3,4 and 5 for their partition? If yes, how do they synchronize if they can reach each other again? Mit freundlichen Grüßen / With best regards Thomas Kießlich Siemens Enterprise Communications GmbH & Co. KG HiPath Applications SEN LIP DA 11 Schertlinstr. 8 81379 Munich, Germany -----Ursprüngliche Nachricht----- Von: Flavio Junqueira [mailto:[EMAIL PROTECTED] Gesendet: Montag, 17. November 2008 13:49 An: zookeeper-user@hadoop.apache.org Betreff: RE: Dynamic server management? Hi Thomas, We currently don't have such a feature of adding and removing servers dynamically, although we would like to, so we'll have it eventually. Without a dynamic mechanism for adding and removing servers, your example is problematic. Suppose that you configure your ensemble to have 3 servers, and then you start only one. Your single server would say: "Hey, I'm alone so I should make progress independently". This is reasonable, right? Well, not really, because you can have the following alternative execution. You start your three servers, but there is a temporary network partition and server 1 cannot talk to servers 2 and 3. Consequently, server 1 will make progress independently of 2 and 3, and their state will diverge. Hope it helps. -Flavio > -----Original Message----- > From: Kiesslich, Thomas [mailto:[EMAIL PROTECTED] > Sent: Monday, November 17, 2008 11:46 AM > To: zookeeper-user@hadoop.apache.org > Subject: Dynamic server management? > > Hi all, > > I am evaluating ZooKeeper as a discovery protocol. I want to change the > number of servers that build up ensemble during runtime of an existing > number servers. Is that possible or do I have to change the configuration > and restart all servers? I found that if you have 3 servers configured and > startup the first it is continously looking for the at least one other > server. Is it really necessary to do that? If the first server does not > find anyone else, it could elect itself as the leader. If the next server > starts up the can redo the election I guess. > Could you please help me with these questions? Thank you. > > > > Mit freundlichen Grüßen / With best regards > Thomas Kießlich > > Siemens Enterprise Communications GmbH & Co. KG > HiPath Applications > > SEN LIP DA 11 > Schertlinstr. 8 > 81379 Munich, Germany > > Phone: +49 (89) 722-32483 > Fax: +49 (89) 722-40560 > Email: [EMAIL PROTECTED] > > Communication for the open minded > www.siemens.de/open > www.siemens.com/open > > Siemens Enterprise Communications GmbH & Co. KG > Managing Directors: Andreas Bernhardt, Reinhard Benditte, > Gerhard Otterbach, Thomas Zimmermann > Registered offices: Munich > Commercial registry Munich, HRA 88546 > WEEE-Reg.-No. DE 27980375 > General Partner: > Siemens Enterprise Communications Management GmbH > Registered offices: Munich > Commercial registry: Munich, HRB 163415 > > Wichtiger Hinweis: Diese Information ist für den Gebrauch durch die Person > oder die Firma/Organisation bestimmt, die in der Empfängeradresse benannt > ist. Wenn Sie nicht der angegebene Empfänger sind, nehmen Sie bitte zur > Kenntnis, daß Weitergabe, Kopieren, Verteilung oder Nutzung des Inhalts > dieser Email-Übertragung unzulässig ist. Falls Sie diese Email irrtümlich > erhalten haben, benachrichtigen Sie den Absender bitte unverzüglich > telefonisch oder durch eine Email. Vielen Dank. > > Important Note: This e-mail may contain trade secrets or privileged, > undisclosed or otherwise confidential information. If you have received > this e-mail in error, you are hereby notified that any review, copying or > distribution of it is strictly prohibited. Please inform us immediately > and destroy the original transmittal. Thank you for your cooperation. >
