Thanks guys. I think I'll start with the replacement of a dead node procedure at least for the first node and I'll monitor the cluster overhead and timing. If I'll see that the overhead and elapsed time are substantially higher I'll try to find some network storage to store the backup. Using the replacement procedure will also be a great practice on production size data, and it will be less dangerous as it's on DR nodes.
On Mon, Dec 22, 2014 at 6:22 PM, Jan Kesten <j.kes...@enercast.de> wrote: > Hi, > > even if recovery like a dead node would work - backup and restore (like my > way with an usb docking station) will be much faster and produce less IO > and CPU impact on your cluster. > > Keep that in Mind :-) > > Cheers, > Jan > > Am 22.12.2014 um 10:58 schrieb Or Sher: > > Great. replace_address works great. > From some reason I thought it won't work with the same IP. > > > On Sun, Dec 21, 2014 at 5:14 PM, Ryan Svihla <rsvi...@datastax.com> wrote: > >> Cassandra is designed to rebuild a node from other nodes, whether a node >> is dead by your hand because you killed it or fate is irrelevant, the >> process is the same, a "new node" can be the same hostname and ip or it can >> have totally different ones. >> >> On Sun, Dec 21, 2014 at 6:01 AM, Or Sher <or.sh...@gmail.com> wrote: >>> >>> If I'll use the replace_address parameter with the same IP address, >>> would that do the job? >>> >>> On Sun, Dec 21, 2014 at 11:20 AM, Or Sher <or.sh...@gmail.com> wrote: >>> >>>> What I want to do is kind of replacing a dead node - >>>> http://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_replace_node_t.html >>>> But replacing it with a clean node with the same IP and hostname. >>>> >>>> On Sun, Dec 21, 2014 at 9:53 AM, Or Sher <or.sh...@gmail.com> wrote: >>>> >>>>> Thanks guys. >>>>> I have to replace all data disks, so I don't have another large enough >>>>> local disk to move the data to. >>>>> If I'll have no choice, I will backup the data before on some other >>>>> node or something, but I'd like to avoid it. >>>>> I would really love letting Cassandra do it thing and rebuild itself. >>>>> Did anybody handled such cases that way (Letting Cassandra rebuild >>>>> it's data?) >>>>> Although there are no documented procedure for it, It should be >>>>> possible right? >>>>> >>>>> On Fri, Dec 19, 2014 at 8:41 AM, Jan Kesten <j.kes...@enercast.de> >>>>> wrote: >>>>> >>>>>> Hi Or, >>>>>> >>>>>> I did some sort of this a while ago. If your machines do have a free >>>>>> disk slot - just put another disk there and use it as another >>>>>> data_file_directory. >>>>>> >>>>>> If not - as in my case: >>>>>> >>>>>> - grab an usb dock for disks >>>>>> - put the new one in there, plug in, format, mount to /mnt etc. >>>>>> - I did an online rsync from /var/lib/cassandra/data to /mnt >>>>>> - after that, bring cassandra down >>>>>> - do another rsync from /var/lib/cassandra/data to /mnt (should be >>>>>> faster, as sstables do not change, minimizes downtime) >>>>>> - if you need adjust /etc/fstab if needed >>>>>> - shutdown the node >>>>>> - swap disks >>>>>> - power on the node >>>>>> - everything should be fine ;-) >>>>>> >>>>>> Of course you will need a replication factor > 1 for this to work ;-) >>>>>> >>>>>> Just my 2 cents, >>>>>> Jan >>>>>> >>>>>> rsync the full contents there, >>>>>> >>>>>> Am 18.12.2014 um 16:17 schrieb Or Sher: >>>>>> >>>>>> Hi all, >>>>>>> >>>>>>> We have a situation where some of our nodes have smaller disks and >>>>>>> we would like to align all nodes by replacing the smaller disks to >>>>>>> bigger >>>>>>> ones without replacing nodes. >>>>>>> We don't have enough space to put data on / disk and copy it back to >>>>>>> the bigger disks so we would like to rebuild the nodes data from other >>>>>>> replicas. >>>>>>> >>>>>>> What do you think should be the procedure here? >>>>>>> >>>>>>> I'm guessing it should be something like this but I'm pretty sure >>>>>>> it's not enough. >>>>>>> 1. shutdown C* node and server. >>>>>>> 2. replace disks + create the same vg lv etc. >>>>>>> 3. start C* (Normally?) >>>>>>> 4. nodetool repair/rebuild? >>>>>>> *I think I might get some consistency issues for use cases relying >>>>>>> on Quorum reads and writes for strong consistency. >>>>>>> What do you say? >>>>>>> >>>>>>> Another question is (and I know it depends on many factors but I'd >>>>>>> like to hear an experienced estimation): How much time would take to >>>>>>> rebuild a 250G data node? >>>>>>> >>>>>>> Thanks in advance, >>>>>>> Or. >>>>>>> >>>>>>> -- >>>>>>> Or Sher >>>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> Or Sher >>>>> >>>> >>>> >>>> >>>> -- >>>> Or Sher >>>> >>> >>> >>> >>> -- >>> Or Sher >>> >> >> >> -- >> >> [image: datastax_logo.png] <http://www.datastax.com/> >> >> Ryan Svihla >> >> Solution Architect >> >> [image: twitter.png] <https://twitter.com/foundev> [image: linkedin.png] >> <http://www.linkedin.com/pub/ryan-svihla/12/621/727/> >> >> DataStax is the fastest, most scalable distributed database technology, >> delivering Apache Cassandra to the world’s most innovative enterprises. >> Datastax is built to be agile, always-on, and predictably scalable to any >> size. With more than 500 customers in 45 countries, DataStax is the >> database technology and transactional backbone of choice for the worlds >> most innovative companies such as Netflix, Adobe, Intuit, and eBay. >> >> > > > -- > Or Sher > > > -- Or Sher
