Re: Column family ID mismatch-Error on concurrent schema modifications
Hi Eric, Zitat von Eric Stevens migh...@gmail.com: @Jens, will inactive CFs be released from C*'s memory after i.e. a few days or when under resource pressure? No, certain memory structures are allocated and will remain resident on each node for as long as the table exists. That's good to know, while not so good for our current design ;) These CFs are used as time buckets, but are to be kept for speedy recovery I would recommend a structure where you include time bucket as part of your primary key and use a single column family for all time buckets. Use TTL's if you want this old data to expire automatically after some certain amount of time. Just FYI: We've had a severe impact on access times when running in single-CF mode, because each bucket itself is quite big (large number of rows, but with small records). That's when we turned to separating data into CFs per time bucket, using TTLs to auto-expire data and deleting the CF once the count of rows dropped to zero. We're talking about millions of (small) records here, not thousands. Per bucket. As we created an architecture that will let us switch between these models, we'll re-test to check the performance impact of both variants. Best regards, Jens
Performance Difference between Batch Insert and Bulk Load
Hi, all, I have a performance question about the batch insert and bulk load. According to the documents, to import large volume of data into Cassandra, Batch Insert and Bulk Load can both be an option. Using batch insert is pretty straightforwards, but there have not been an ‘official’ way to use Bulk Load to import the data (in this case, i mean the data was generated online). So, i am thinking first clients use CQLSSTableWriter to create the SSTable files, then use “org.apache.cassandra.tools.BulkLoader” to import these SSTables into Cassandra directly. The question is can I expect a better performance using the BulkLoader this way comparing with using Batch insert? I am not so familiar with the implementation of Bulk Load. But i do see a huge performance improvement using Batch Insert. Really want to know the upper limits of the write performance. Any comment will be helpful, Thanks! - Dong
does safe cassandra shutdown require disable binary?
I’m trying to figure out a safe way to do a rolling restart. http://devblog.michalski.im/2012/11/25/safe-cassandra-shutdown-and-restart/ It has the following command which make sense: root@cssa01:~# nodetool -h cssa01.michalski.im disablegossiproot@cssa01:~# nodetool -h cssa01.michalski.im disablethriftroot@cssa01:~# nodetool -h cssa01.michalski.im drain … but I don’t think this takes into consideration CQL. So you would first disablethrift, then disablebinary anything else needed in modern Cassandra ? -- Founder/CEO Spinn3r.com Location: *San Francisco, CA* blog: http://burtonator.wordpress.com … or check out my Google+ profile https://plus.google.com/102718274791889610666/posts http://spinn3r.com
Cassandra add a node and remove a node
Hi, I need to Add new Node and remove existing node. Should I first remove the node and then add a new node or Add new node and then remove existing node. Which practice is better and things I need to take care? regards Neha
Re: Cassandra add a node and remove a node
Hi Neha, Generally best practice is to add the new node before removing the old one. This is especially important if the cluster’s resources (such as available disk space) are low. Also, adding a node usually asserts that the node is functioning correctly (check logs) before decommisioning the old node. See [1]. [1] http://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_replace_live_node.html Cheers, Jens ——— Jens Rantil Backend engineer Tink AB Email: jens.ran...@tink.se Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter On Mon, Dec 1, 2014 at 7:15 AM, Neha Trivedi nehajtriv...@gmail.com wrote: Hi, I need to Add new Node and remove existing node. Should I first remove the node and then add a new node or Add new node and then remove existing node. Which practice is better and things I need to take care? regards Neha
