Hi, It depends on your replication factor and consistency levels used.
If you are not using consistency level of ALL in your applications and your replication factor is 3, then you usually don’t need to stop your frontend applications for the upgrade. If replication factor = 2 then you need to run consistency level of one (or local_one or any) in your applications. You cannot use quorum or all, or your queries start failing. If replication factor = 1, your queries start failing when you upgrade one node. Hannu > On 3 May 2018, at 10:12, Xiangfei Ni <xiangfei...@cm-dt.com> wrote: > > Thanks Hannu, > Another question is that,do I need to stop the frontend application during > the upgrade? > I have 3 nodes cluster,let’s say: > Cassandra01 > Cassandra02 > Cassandra03 > > First I upgrade the cassandra01 node, > 1,nodetool drain > 2,backup data > 3,install new binary > 4,configure the configuration file > 5,start Cassandra service > 6,nodetool upgrade > > Then another node one by one > > do I need to stop the frontend application during the upgrade? > > > > Best Regards, > > 倪项菲/ David Ni > 中移德电网络科技有限公司 > Virtue Intelligent Network Ltd, co. > > Add: 2003,20F No.35 Luojia creative city,Luoyu Road,Wuhan,HuBei > Mob: +86 13797007811|Tel: + 86 27 5024 2516 > > 发件人: Hannu Kröger <hkro...@gmail.com> > 发送时间: 2018年5月3日 15:00 > 收件人: user <firstname.lastname@example.org> > 主题: Re: upgrade from 3.9 to 3.11.2 > > Hello, > > it never hurts to run “nodetool upgradesstables" after the upgrade. It’s a > no-op if there is nothing to upgrade. > > Hannu > > > On 3 May 2018, at 09:57, Xiangfei Ni <xiangfei...@cm-dt.com > <mailto:xiangfei...@cm-dt.com>> wrote: > > Hi Community > I have a question regarding upgrading Cassandra from 3.9 to 3.11.2, > Do I need to run nodetool upgradesstables when I do the upgrade?we know > that we don’t need to run this command when we do minor version upgrade.But > from 3.9 to 3.11.2,I have no idea. > Also I suggest that the community should have official article about the > upgrading,everytime I do upgrade we can just google the posts via internet. > > > Best Regards, > > 倪项菲/ David Ni > 中移德电网络科技有限公司 > Virtue Intelligent Network Ltd, co. > > Add: 2003,20F No.35 Luojia creative city,Luoyu Road,Wuhan,HuBei > Mob: +86 13797007811|Tel: + 86 27 5024 2516