Re: Quorum read after quorum write guarantee
On 10/03/2013, at 16:49, Chuan-Heng Hsiao wrote: > However, my guess is that cassandra only guarantee that > if you successfully write and you successfully read, then quorum will > give you the latest data. That's what I thought, but that's not what I'm seeing all the time. I have no errors reading or writing. André
Re: Quorum read after quorum write guarantee
Yes, same thread. Cassandra 1.1.5 btw. Sent from my iPhone On 10/03/2013, at 16:47, Dave Brosius wrote: > is the read and write happening on the same thread? > > On 03/10/2013 12:00 PM, André Cruz wrote: >> Hello. >> >> In my application it sometimes happens that I execute a multiget (I use >> pycassa) to fetch data that I have just inserted. I use quorum writes and >> reads, and my RF is 3. >> >> I've noticed that sometimes (1 in 1000 perhaps) an insert followed (300ms >> after) by a multiget will not find the just inserted data. Is this normal? >> Or is something wrong? Can there be some delay to obtain the inserted data >> even with quorum? >> >> Best regards, >> André >
Re: Quorum read after quorum write guarantee
Hi André, I am just a user of cassandra and did not look into the code deeply. However, my guess is that cassandra only guarantee that if you successfully write and you successfully read, then quorum will give you the latest data. not finding the just inserted data may be due to the failure of successfully write or the failure of successfully read. if it is the failure of successfully write, then pycassa should give you some error message. if it is the failure of successfully read, then pycassa may give you timeout error or not-found error. To test it fairly, it is better to setup the scenario as continuously write/read same key/column name, but with different column value. Then you should be able to see that when you read, either you read the latest data (successful write/read), or you read the old data (fail write/success read), or you read nothing (fail read) Hopefully my guess is on the right track, and hopefully you understand what I mean. Sincerely, Hsiao On Mon, Mar 11, 2013 at 12:00 AM, André Cruz wrote: > Hello. > > In my application it sometimes happens that I execute a multiget (I use > pycassa) to fetch data that I have just inserted. I use quorum writes and > reads, and my RF is 3. > > I've noticed that sometimes (1 in 1000 perhaps) an insert followed (300ms > after) by a multiget will not find the just inserted data. Is this normal? Or > is something wrong? Can there be some delay to obtain the inserted data even > with quorum? > > Best regards, > André
Re: Quorum read after quorum write guarantee
is the read and write happening on the same thread? On 03/10/2013 12:00 PM, André Cruz wrote: Hello. In my application it sometimes happens that I execute a multiget (I use pycassa) to fetch data that I have just inserted. I use quorum writes and reads, and my RF is 3. I've noticed that sometimes (1 in 1000 perhaps) an insert followed (300ms after) by a multiget will not find the just inserted data. Is this normal? Or is something wrong? Can there be some delay to obtain the inserted data even with quorum? Best regards, André
Quorum read after quorum write guarantee
Hello. In my application it sometimes happens that I execute a multiget (I use pycassa) to fetch data that I have just inserted. I use quorum writes and reads, and my RF is 3. I've noticed that sometimes (1 in 1000 perhaps) an insert followed (300ms after) by a multiget will not find the just inserted data. Is this normal? Or is something wrong? Can there be some delay to obtain the inserted data even with quorum? Best regards, André
Re: Running cassandra across nat?
In some cases you can do this using the broadcast address, which is different then the listen and rpc address. But if nothing is route-able ie NAT I do not think it is possible. On Sun, Mar 10, 2013 at 10:05 AM, Илья Шипицин wrote: > Hello! > > Is it possible to run cluster in 2 datacenters which are not routable? > Each datacenter is running its own lan prefixes, however lan are not > routable across datacenters. > > Cheers, > Ilya Shipitsin >
Running cassandra across nat?
Hello! Is it possible to run cluster in 2 datacenters which are not routable? Each datacenter is running its own lan prefixes, however lan are not routable across datacenters. Cheers, Ilya Shipitsin
