Re: How to make compaction run faster?

I believe that compaction occurs on the data directories and not in the commitlog. Yes, compaction only works on the data files. When I ran iostat; I see await 26ms to 30 ms for my commit log disk. My CPU is less than 18% used. How I reduce the disk latency for my commit log disk. They

Re: How to stop Cassandra and then restart it in windows?

Cassandra -f So I believe that's why it is getting started as service. Starts it in the foreground. Sorry I dont use windows. Try moving the install and see what complains at startup, check the system logs to see if there is an error. Cheers - Aaron Morton Freelance

Re: Key-Token mapping in cassandra

All rows with the same key go on the same nodes. So if you use the same row key in different CF's they will be on the same nodes. i.e. have CF's called Image, Documents, Meta and store rows in all of them with the 123 key. Cheers - Aaron Morton Freelance Cassandra Consultant

Re:

ERROR 08:40:42,684 Error occurred during processing of message. java.lang.StringIndexOutOfBoundsException: String index out of range: -214741811 1 at java.lang.String.checkBounds(String.java:397) at java.lang.String.init(String.java:442) at

Re:

I use hector On Thu, Apr 18, 2013 at 1:35 PM, aaron morton aa...@thelastpickle.comwrote: ERROR 08:40:42,684 Error occurred during processing of message. java.lang.StringIndexOutOfBoundsException: String index out of range: -214741811 1 at

RE: differences between DataStax Community Edition and Cassandra package

Thank you Aaron. From: aaron morton [mailto:aa...@thelastpickle.com] Sent: woensdag 17 april 2013 20:20 To: user@cassandra.apache.org Subject: Re: differences between DataStax Community Edition and Cassandra package It's the same as the Apache version, but DSC comes with samples and the free

Re: differences between DataStax Community Edition and Cassandra package

whats CDFS ? I am sure you are not referring iso9660, e.g. CD-ROM filesystem? :) On Wed, Apr 17, 2013 at 10:42 PM, Robert Coli rc...@eventbrite.com wrote: On Wed, Apr 17, 2013 at 11:19 AM, aaron morton aa...@thelastpickle.comwrote: It's the same as the Apache version, but DSC comes with

How to configure Cassandra params to handle heavy write, light read, short TTL scenario

Dear buddies, We are using Cassandra to handle a tech scenario like the following: 1. A table using a Long as Key, and has one and only one Integer as a ColumnFamily, with 2 hours as the TTL. 2. The wps(write per second) is 45000, the qps(read per second) would be about 30 - 200. 3. There isn't

Re: differences between DataStax Community Edition and Cassandra package

Probably Robert meant CFS: http://www.datastax.com/wp-content/uploads/2012/09/WP-DataStax-HDFSvsCFS.pdf :-) W dniu 18.04.2013 14:10, Nikolay Mihaylov pisze: whats CDFS ? I am sure you are not referring iso9660, e.g. CD-ROM filesystem? :) On Wed, Apr 17, 2013 at 10:42 PM, Robert Coli

Unable to drop secondary index

As stated in topic, I'm unable to drop secondary index either by using cli or cqlsh. In both cases it looks like to command is processed properly (some uuid shows up in cli, no output in cqlsh), I can see in logs that schema is going to be updated (index name and type are set to null) and

Re: InvalidRequestException: Start key's token sorts after end token

Hi all, we solved the problem ... first we updated the Cassandra for 1.2.3 version and after another exception was launched No hosts to borrow from and we discovered that the command ConnectionPoolConfigurationImpl(...).setConnectTimeout(-1) was the cause ... and we put

Re: differences between DataStax Community Edition and Cassandra package

I thought so, sorry to ask in this thread, but from some time I am wondering how CFS can be installed on normal Cassandra? On Thu, Apr 18, 2013 at 3:23 PM, Michal Michalski mich...@opera.com wrote: Probably Robert meant CFS: http://www.datastax.com/wp-**

Client lib

Hi - We are planning to develop a custom client using the Thrift API for Cassandra. Are these available from the JMX ? - Can cassandra provide info abt node status? - DC Failover detection (data center down, vs some nodes are down) - How to get load info from each node? Thanks, Kanwar

Re: Client lib

You can get the topology info from thrift's describe_ring. But you can not get host/gossip status through thrift. It does make sense as something to add. In the native protocol and with the fat client(storage proxy) you can hook into these events. An example of this is here (fat client):

Moving cluster

Hi, What is the best pratice to move from a cluster of 7 nodes (m1.xlarge) to 3 nodes (hi1.4xlarge). Thanks,

Ec2Snitch to Ec2MultiRegionSnitch

Hi, The company I work for is having so much success that we are expanding worldwide :). We have to deploy our Cassandra servers worldwide too in order to improve the latency of our new abroad customers. I am wondering about the process to grow from one data center to a few of them. First thing

Re: Moving cluster

I would say add your 3 servers to the 3 tokens where you want them, let's say : { 0: { 0: 0, 1: 56713727820156410577229101238628035242, 2: 113427455640312821154458202477256070485 } } or these token -1 or +1 if you already have these token used. And then just

Re: Moving cluster

This should work. Another option is to follow a process similar to what we recently did. We recently and successfully upgraded 12 instances from large to xlarge instances in AWS. I chose not to replace nodes as restoring data from the ring would have taken significant time and put the

Re: How to make compaction run faster?

Hi Alexis, Yes compaction happens on data files - 1. What my disk latency is high for SSDs which been only used for commit log 2. Why my compaction is not catching up with my write traffic in spite of low CPU, low memory and low JVM usage. I am adding more details to this thread. Thanks, Jayant

Re: How to make compaction run faster?

Jay, Do you have metrics of disk usage on the disks that contains your data directories? Compaction operates over those files, may be your problems are with those disks and not with the disks that have the commitlog. On Thu, Apr 18, 2013 at 1:33 PM, Jay Svc jaytechg...@gmail.com wrote: Hi

Using mapvarchar, varchar type with composite primary key causes significant performance decrease

Hi, I'm trying to persist some event data, I've tried to identify the bottleneck, and it seems to work like that: If I create a table with primary key based on (application, environment, type and emitted_at): CREATE TABLE events (application varchar, environment varchar, type varchar,

Re: How to make compaction run faster?

Hi Aaron, Alexis, Thanks for reply, Please find some more details below. *Core problems:* Compaction is taking longer time to finish. So it will affect my reads. I have more CPU and memory, want to utilize that to speed up the compaction process. *Parameters used:* 1. SSTable size: 500MB

Re: How to make compaction run faster?

Looks like formatting is bit messed up. Please let me know if you want the same in clean format. Thanks, Jay On Thu, Apr 18, 2013 at 12:05 PM, Jay Svc jaytechg...@gmail.com wrote: Hi Aaron, Alexis, Thanks for reply, Please find some more details below. *Core problems:* Compaction is

Re: How to make compaction run faster?

Jay, await, according to iostat's man page it is the time of a request to the disk to get served. You may try changing the io scheduler. I've read that noop it's recommended for SSDs, you can check here http://goo.gl/XMiIA Regarding compaction, a week ago we had serious problems with compaction

Re: Repair hanges on 1.1.4

Looks like there are no repairs running. Is this just an issue with ops centre? Try restarting the ops centre agent: sudo service opscenter-agent restart Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 18/04/2013,

Re: How to configure Cassandra params to handle heavy write, light read, short TTL scenario

Is that possible that we could make some configuration, so there will be like a mem_table queue in the memory, like there are 4 mem_tables in the memory, from mem1, mem2, mem3, mem4 based on time series, and the Cassandra will flush mem1, and once there is a mem5 is full, it will flush the

Re: How to make compaction run faster?

We have tried very hard to speed up lcs on 1.1.6 with no luck. It seems to be single threaded and not much parallelism you can achieve. 1.2 does come with parallel lcs which should help. One more thing to try is to enlarge the sstable size which will reduce the number of SSTable. It *might*

Re: Unable to drop secondary index

Was the schema created with CQL or the CLI ? (It's not a good idea to manage one with the other) Can you provide the schema after the update and the update cf statement? Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com

Re: differences between DataStax Community Edition and Cassandra package

sorry to ask in this thread, but from some time I am wondering how CFS can be installed on normal Cassandra? CFS is part of the Data Stax enterprise product. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On

Re: Using mapvarchar, varchar type with composite primary key causes significant performance decrease

After about 1-2K inserts I get significant performance decrease. A decrease in performance doing what ? Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 19/04/2013, at 4:43 AM, Oleksandr Petrov

Re: How to make compaction run faster?

Hi Alexis, Thank you so much for inputs. Let me try those suggested options. I will also look forward to see if you have any more suggestions on our Compaction. Thanks, Jay On Thu, Apr 18, 2013 at 1:03 PM, Alexis Rodríguez arodrig...@inconcertcc.com wrote: Jay, await, according to

Re: Moving cluster

This is roughly the lift and shift process I use. Note that disabling thrift and gossip does not stop an existing repair session. So I often drain and then shutdown, and copy the live data dir rather than a snapshot dir. Cheers - Aaron Morton Freelance Cassandra Consultant

Re: How to make compaction run faster?

Parameters used: • SSTable size: 500MB (tried various sizes from 20MB to 1GB) • Compaction throughput mb per sec: 250MB (tried from 16MB to 640MB) • Concurrent write: 196 (tried from 32 to 296) • Concurrent compactors: 72 (tried disabling to making it 172) •

Re: How to make compaction run faster?

Thanks Aaron, Please find answers to your questions. 1. I started test with default parameters the compaction is backing up. So went for various options. 2. The data is on RAID10. 3. As I watched Disk latency on DSE Opscenter as well as on iostat the await is always 35 to 40 ms for longer period

RE: How to make compaction run faster?

Use the community edition and try it out. Compaction has nothing to do with the CPU. It's all on raw disk speed. What kind of disks do you have ? 7.2k, 10k, 15k RPM ? Are your keys unique or you are doing updates ? if unique writes, I would not worry about compaction too much and let it run

Re: 1.1.9 to 1.2.3 upgrade issue

Yes, the exceptions were only on the 1.1.9 nodes. Unfortunately, couldn't complete the upgrade because it was adversely affecting the applications using the cluster during that time. Best, John On Tue, Apr 16, 2013 at 2:03 PM, aaron morton aa...@thelastpickle.comwrote: Is this a known

Re: Using mapvarchar, varchar type with composite primary key causes significant performance decrease

Write performance decreases. Reads are basically blocked, too. Sometimes I have to wait 3-4 seconds to get a count even though there're only couple of thousand small entries in a table. On Thu, Apr 18, 2013 at 8:37 PM, aaron morton aa...@thelastpickle.comwrote: After about 1-2K inserts I get

Re: How to configure Cassandra params to handle heavy write, light read, short TTL scenario

Hi Aaron, 1. A timeout more than 10ms to us is the max value we could accept 2. It is a random key access, not a range scan. 3. We have only one column family only for that keyspace, we select the columns. Thanks. Best wishes, Stanley Xu On Fri, Apr 19, 2013 at 2:22 AM, aaron morton

Datastax API which uses Binary protocol- Quick question

I have started working with Cassandra database. I am planning to use Datastax API to upsert/read into/from cassandra database. I am totally new to this Datastax API (which uses new Binary protocol) and I am not able to find lot of documentations as well which have some proper examples. I am not

Re: Key-Token mapping in cassandra

Hi Ravi Key1 -- 123/IMAGE Key2 -- 123/DOCUMENTS Key3 -- 123/MULTIMEDIA Which one is your ROW KEY ?? It is Key1,Key2,Key3? On Thu, Apr 18, 2013 at 3:56 PM, aaron morton aa...@thelastpickle.comwrote: All rows with the same key go on the same nodes. So if you use the same row key in

Re: Repair Freeze / Gossip Invisibility / EC2 Public IP configuration

We don't use default ports. Woops! Now I advertised mine. I did try disabling internode compression for all in cassandra.yaml but still it did not work. I have to open the insecure storage port to public ips. On Tue, Apr 16, 2013 at 4:59 PM, Edward Capriolo edlinuxg...@gmail.comwrote: So