<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=us-ascii"> <META content="MSHTML 6.00.2900.3086" name=GENERATOR></HEAD> <BODY> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=632154417-01062007>Sorry, forgot the error message in here.</SPAN></FONT></DIV> <DIV><STRONG><FONT face=Tahoma size=2></FONT></STRONG> </DIV><FONT face=Arial color=#0000ff size=2></FONT><BR> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT face=Tahoma size=2><B>From:</B> linux-cluster-bounces@redhat.com [mailto:linux-cluster-bounces@redhat.com] <B>On Behalf Of </B>Robert Gil<BR><B>Sent:</B> Friday, June 01, 2007 1:43 PM<BR><B>To:</B> linux clustering<BR><B>Subject:</B> RE: [Linux-cluster] MySQL Failover / Failback<BR></FONT><BR></DIV> <DIV></DIV> <DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV><STRONG><FONT face=Tahoma size=2></FONT></STRONG><STRONG><FONT face=Tahoma size=2></FONT></STRONG><STRONG><FONT face=Tahoma size=2></FONT></STRONG><STRONG><FONT face=Tahoma size=2></FONT></STRONG><STRONG><FONT face=Tahoma size=2></FONT></STRONG><BR> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT face=Tahoma size=2><B>From:</B> linux-cluster-bounces@redhat.com [mailto:linux-cluster-bounces@redhat.com] <B>On Behalf Of </B>Jeff Stoner<BR><B>Sent:</B> Friday, June 01, 2007 1:21 PM<BR><B>To:</B> linux clustering<BR><B>Subject:</B> RE: [Linux-cluster] MySQL Failover / Failback<BR></FONT><BR></DIV> <DIV></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007>Sounds like you've got several things happening all at once. If you are not using MySQL Cluster, then you will probably have an active/passive setup, in which MySQL will be running on only one node. If you are using MySQL Cluster, why are you using Redhat Cluster?</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007></SPAN></FONT> </DIV> <DIV dir=ltr align=left><FONT face=Arial color=#008000 size=2><SPAN class=301264516-01062007><SPAN class=183483917-01062007>Yes, it is using mysql replication NOT mysql cluster. It is active / passive. One node is rw (master) the other is ro (slave).</SPAN></SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007></SPAN></FONT> </DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007>Replication? Are you referring to MySQL Replication? What is replicating where? Are the slaves a part of the Redhat Cluster? If you simply mean will replication "break" if MySQL fails over then no. Replication on the slave will retry connecting to the master (according to the connection retry settings in MySQL.) Also, you must use the Redhat Cluster-controlled IP when establishing replication and not the IP of any particular node (for obvious reasons.)</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007></SPAN></FONT> </DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007>For my MySQL databases built on Redhat Cluster, I specify my service as follows:</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007></SPAN></FONT> </DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007><service autostart="1" domain="mysql-fail-domain" name="mysql5-service"><BR> <ip ref="10.2.2.2"/><BR> <fs ref="mysqlfs"/><BR> <script ref="mysqld"/><BR></service><BR></SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN class=301264516-01062007>The filesystem resource is a slice of SAN accessible by all nodes in the cluster. The script is a (modified) /etc/init.d/mysqld script.</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2></FONT> </DIV> <DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2></FONT> </DIV> <DIV dir=ltr align=left><SPAN class=183483917-01062007><FONT face=Arial color=#008000 size=2>What does your resource section look like for the ip address? I keep getting the following errors (posted in another message)</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=183483917-01062007><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=183483917-01062007><FONT face=Arial color=#008000 size=2>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <notice> Starting disabled service mastervip<BR>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <notice> start on ip:192.168.2.100 returned 1 (generic error)<BR>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <warning> #68: Failed to start mastervip; return value: 1<BR>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <notice> Stopping service mastervip<BR>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <notice> Service mastervip is recovering<BR>Jun 1 13:29:10 melpsjssdbs01 clurgmgrd[5346]: <warning> #71: Relocating failed service mastervip<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <warning> #70: Attempting to restart service mastervip locally.<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <notice> Recovering failed service mastervip<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <notice> start on ip:192.168.2.100 returned 1 (generic error)<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <warning> #68: Failed to start mastervip; return value: 1<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <notice> Stopping service mastervip<BR>Jun 1 13:29:11 melpsjssdbs01 clurgmgrd[5346]: <notice> Service mastervip is stopped<BR></FONT></SPAN></DIV> <P><FONT size=2>--Jeff<BR><BR>Service Engineer<BR>OpSource Inc.<BR><BR>"The Message of the Day is /etc/motd"<BR></FONT></P> <DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV><FONT face=Arial color=#0000ff size=2></FONT><FONT face=Arial color=#0000ff size=2></FONT><FONT face=Arial color=#0000ff size=2></FONT><FONT face=Arial color=#0000ff size=2></FONT><BR> <BLOCKQUOTE dir=ltr style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px"> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left> <HR tabIndex=-1> <BR></DIV> <DIV></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>I am curious if anyone knows the best practices for this? Several use cases include</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>Note: We are choosing to use a vip for the two nodes to make the failover change transparent to the application side.</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>1) Node 1 (master) dies</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2> -How do we enable "sticky" failover so that it does not then fail back to Node 1</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2> -Is Node 2 active all the time or is the service completely shut off? And if its off, how would replication happen?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007> <FONT face=Arial size=2>-How do failover domains work in this case?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>2) Node 2 (Master) Node 1 recovered</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007> <FONT face=Arial size=2>-How does replication continue again?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007> <FONT face=Arial size=2>-How does the master slave relationship change? Is this automated, or does it require manual intervention? Should we be using DRDB?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>3) Node 1 (master) Node 2 (slave) - network connectivity dies on node 1</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007> <FONT face=Arial size=2>-There is an IP resource available, but how does this monitor and handle failover?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007> <FONT face=Arial size=2>-How can I move the vip in the event of a failure? Do I need to manually script this?</FONT></SPAN></DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=924030814-01062007><FONT face=Arial size=2>With the vip failover, do I attach the vip resource to the mysql resource in the failover domain for those two nodes? What happens if I do this?</FONT></SPAN></DIV> <DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT> </DIV></BLOCKQUOTE></BODY></HTML>