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.
