You can increase system open files,
also if you compact, open files will go down.
On Mon, Jan 22, 2018 at 10:19 AM, Dor Laor wrote:
> It's a high number, your compaction may run behind and thus
> many small sstables exist. However, you're also taking the
> number of network connection in the cal
HI
We have 2 - 3 installations with single node Cassandra. They working fine,
no problems there,
except if Cassandra stops, everything stops. Even on one node, we usually
"rolling" 500-600 GB data, sometimes even 2-3 TB. We use mostly standard
configuration with almost no changes there.
Here are
s can
> accept reads & writes, and your writes will be replicated to all replicas
> at the consistency level provided (as per the earlier doc).
>
> Does that help?
>
> On Thu, Apr 30, 2015 at 5:09 AM Nikolay Tikhonov <
> tikhonovnico...@gmail.com> wrote:
>
>>
15 at 8:56 AM, Nikolay Tikhonov <
> tikhonovnico...@gmail.com> wrote:
>
>> I try to understand how to Cassandra supports data consistency and
>> compare it with other distributed caches.
>>
>
> For the record, Cassandra is not a distributed cache.
>
> =Rob
>
>
Hi,
I try to understand how to Cassandra supports data consistency and compare
it with other distributed caches. Hazelcast and Apache Ignite products have
primary and backups. This approach allows to support read/write consistency
if client code will read/write to primary node. User's operation wi
Hi
from some time I try to find the structure of sstable is it documented
somewhere or can anyone explain it to me
I am speaking about "hex dump" bytes stored on the disk.
Nick.
Hi Tyler,
sorry for very stupid question - what is a collection ?
Nick
On Wed, Dec 31, 2014 at 6:27 PM, Tyler Hobbs wrote:
> Overwriting an entire collection also results in a tombstone being
> inserted.
>
> On Wed, Dec 24, 2014 at 7:09 AM, Ryan Svihla wrote:
>
>> You should probably ask on t
my 2 cents:
try major compaction on the column family with TTL's - for sure will be
faster than full rebuild.
also try not cassandra related things, such check and remove old log files,
backups etc.
On Wed, Oct 1, 2014 at 9:34 AM, Sumod Pawgi wrote:
> In the past in such scenarios it has helpe
sorry, probably somebody mentioned it, but did you checked global limit?
cat /proc/sys/fs/file-max
cat /proc/sys/fs/file-nr
On Mon, May 5, 2014 at 10:31 PM, Bryan Talbot wrote:
> Running
>
> #> cat /proc/$(cat /var/run/cassandra.pid)/limits
>
> as root or your cassandra user will tell you what
the real question is - if you want the email to be unique, why use
"surrogate" primary key as UUID.
I wonder what UUID gives you at all?
If you want to have non email primary key, why not use md5(email) ?
On Wed, May 7, 2014 at 2:19 AM, Tyler Hobbs wrote:
>
> On Mon, May 5, 2014 at 10:27 AM
Hi
my two cents - before doing anything else, make sure clocks are
synchronized to the millisecond.
ntp will do so.
Nick.
On Mon, Oct 7, 2013 at 9:02 AM, Alexander Shutyaev wrote:
> Hi all,
>
> We have encountered the following problem with cassandra.
>
> * We use *cassandra v2.0.0* from *Data
Hi,
we have cassandra 1.2.6, single node.
we have a website there, running on different server.
recently we noticed that we have 40 MBit traffic from cassandra server to
the web server
we use phpcassa.
on ops center we have "KeyCache Hits" value around 2000 .
I found the most used CF's from n
mi-ordered partitioner - instead of single MD5,
> to have two MD5's.
>
> Sounds interesting. But, we need a fully ordered result.
>
> Anyway, I will try with the latest version.
>
> Thanks,
> Takenori
>
>
> On Thu, Aug 22, 2013 at 6:12 PM, Nikolay Mihaylov wrote:
my five cents -
token and key are not same. it was like this long time ago (single MD5
assumed single key)
if you want ordered, you probably can arrange your data in a way so you can
get it in ordered fashion.
for example long ago, i had single column family with single key and about
2-3 M columns
thanks
It will use the Index Sample (RAM) first, then it will use "full" Index
(disk) and finally it will read data from SSTable (disk). There's no such
thing like "collision" in this case.
so it still have 2 seeks :)
where I can see the internal structure of the sstable i tried to find it
docum
Hi
I am researching various hash-tables and b-trees on disk.
while I researched, I has a thoughts about cassandra sstables that I want
to verify it here.
1. cassandra sstable uses sequential disk I/O when created. e.g. disk head
write it from the beginning to the end. Assuming the disk is not
fr
Hi
please note that when you drop column family, the data on the disk is not
deleted.
this is something you should do yourself.
>> Do the files get deleted on GC/server restart?
the question actually translates - do the column family existed after the
restart?
John pls correct me if I am explai
Did you synchronized the clocks between servers?
On Thu, May 23, 2013 at 9:32 AM, Tamar Fraenkel wrote:
> Hi!
> I have Cassandra cluster with 3 node running version 1.0.11.
>
> I am using Hector HLockManagerImpl, which creates a keyspace named
> HLockManagerImpl and CF HLocks.
> For some reason
do you use vnodes ?
On Fri, May 10, 2013 at 10:19 AM, 杨辉强 wrote:
> Hi, all
> I use ./bin/nodetool -h 10.21.229.32 ring
>
> It generates lots of info of same host like this:
>
> 10.21.229.32 rack1 Up Normal 928.3 MB24.80%
>8875305964978355793
> 10.21.229.32 rack1
y very well, but not with real live data.
version for Redis is included too for easy testing.
Nikolay.
On Mon, Apr 22, 2013 at 2:19 AM, Utkarsh Sengar wrote:
> Difference b/w cqlsh and cli is documented by the datastax guys here
> nicely: http://www.datastax.com/support-forums/t
Is there alternative file systems running on top of cassandra?
On Fri, Apr 19, 2013 at 7:44 PM, Robert Coli wrote:
> On Fri, Apr 19, 2013 at 4:18 AM, Goktug YILDIRIM
> wrote:
> >
> > I am sorry if this a very well know topic and I missed that. I wonder
> why one must use CFS. What is unavaila
FS.pdf<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, 20
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 wrote:
> On Wed, Apr 17, 2013 at 11:19 AM, aaron morton wrote:
>
>> It's the same as the Apache version, but DSC comes with samples and the
>> free version of Ops Centr
dra-env.sh or
> cassandra.yaml revert them. Generally C* will do the right thing and not
> OOM, unless you are trying to store a lot of data on a node that does not
> have enough memory. See this thread for background
> http://www.mail-archive.com/user@cassandra.apache.org/msg25762.htm
at does not
> have enough memory. See this thread for background
> http://www.mail-archive.com/user@cassandra.apache.org/msg25762.html
>
> Cheers
>
> -
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickl
For one project I will need to run cassandra on following dedicated servers:
Single CPU XEON 4 cores no hyper-threading, 8 GB RAM, 12 TB locally
attached HDD's in some kind of RAID, visible as single HDD.
I can do cluster of 20-30 such servers, may be even more.
The data will be huge, I am estim
And the final solution
http://unbxd.com/blog/2012/07/java-and-ksoftirqd-100-cpu-due-to-leap-second/
Doing $ date -s "`date`" solved the problem.
30.07.2012, 16:09, "Nikolay Kоvshov" :
> You mean using swap memory? I have total of 48G of RAM and Cassandra never
>
of July 2012, Nikolay Kоvshov wrote:
>
>> - JNA is not installed on both machines
>
> So your GC times may be strongly [1] affected by swapping.
> IIRC, also snapshotting is more expensive and may trigger more swapping.
> I would start with turning JNA mlockall on [2].
>
&
- JNA is not installed on both machines
30.07.2012, 14:44, "Mateusz Korniak" :
> On Monday 30 of July 2012, Nikolay Kоvshov wrote:
>
>> What I plan to compare between 'bad' cluster and 'good' cluster:
>>
>> - Configs, schemas, data etc: s
java version : same
- RAM and CPU : 'bad' cluster has more
- Ubuntu version
- Networking
- What else???
26.07.2012, 10:25, "Nikolay Kоvshov" :
> Sun Java 6 didn't help it at all
>
> Sar shows no special activity on the long GC times
>
> And I have r
13:07, "Joost van de Wijgerd" :
> You are better off using Sun Java 6 to run Cassandra. In the past
> there were issues reported on 7. Can you try running it on Sun Java 6?
>
> kind regards
>
> Joost
>
> On Tue, Jul 24, 2012 at 10:04 AM, Nikolay Kоvshov wrote:
>
&g
13:07, "Joost van de Wijgerd" :
> You are better off using Sun Java 6 to run Cassandra. In the past
> there were issues reported on 7. Can you try running it on Sun Java 6?
>
> kind regards
>
> Joost
>
> On Tue, Jul 24, 2012 at 10:04 AM, Nikolay Kоvshov wrote:
&g
I ran sar only recently after your advice and did not meet any huge GC-s on
that server
At 08:14 there was a GC lasting 4.5 seconds, that's not five minutes of course,
but also quite an unpleasant value;
Still I'm waiting for big GC values and will provide according sar logs.
07:25:01 PM pgp
pping. Also which jvm do you use?
>
> kind regards
>
> Joost
>
> On Mon, Jul 23, 2012 at 10:07 AM, Nikolay Kоvshov wrote:
>
>> 21th I have mirgated to cassandra 1.1.2 but see no improvement
>>
>> cat /var/log/cassandra/Earth1.log | grep "GC for"
>&
I have a testing cluster cassandra 1.1.2 with default memory and cache
settings, 1 CF, 1 KS, RF = 2
This is an empty cluster
10.111.1.141datacenter1 rack1 Up Normal 43.04 KB100.00%
0
10.111.1.142datacenter1 rack1
ave a lot of CF's and/or secondary indexes ?
> Can you see log lines about the "liveRatio" for your cf's ?
> I would upgrade to 1.0.10 before getting too carried away though.
> Cheers
>
> -
> Aaron Morton
> Freelance Developer
> @aaronmorton
>
This is a cluster of 2 nodes, each having 8G of operating memory,
replicationfactor=2
Write/read pressure is quite low and almost never exceeds 10/second
>From time to time (2-3 times in a month) I see GC activity in logs and for
>this time cassandra stops responding to requests which results i
be of use.
13.02.2012, 17:19, "Dominic Williams" :
> Hi Nikolay,Some points that may be useful:
> 1/ auto_bootstrap = true is used for telling a new node to join the ring (the
> cluster). It has nothing to do with hinted handoff
> 2/ both of your nodes seem to be using the s
Hello everybody
I have a very simple cluster containing 2 servers. Replication_factor = 2,
Consistency_level of reads and writes = 1
10.111.1.141datacenter1 rack1 Up Normal 1.5 TB 100.00%
vjpigMzv4KkX3x7z
10.111.1.142datacenter1 rack1 Up Normal 1.41 TB
assandra to guard against OOM, you must configure
> nodes such that the max memory usage on each node, that is max size all your
> caches and memtables can potentially grow to, is less than your heap size.
>
> From: Nikolay Kоvshov [nkovs...@
//www.datastax.com/docs/0.7/troubleshooting/index#nodes-are-dying-with-oom-errors
>
> On Fri, Apr 22, 2011 at 8:00 AM, Nikolay Kоvshov ;;
> wrote:
>> I am using Cassandra 0.7.0 with following settings
>>
>> binary_memtable_throughput_in_mb: 64
>> in_memory
I am using Cassandra 0.7.0 with following settings
binary_memtable_throughput_in_mb: 64
in_memory_compaction_limit_in_mb: 64
keys_cached 1 million
rows_cached 0
RAM for Cassandra 2 GB
I run very simple test
1 Node with 4 HDDs (1 HDD - commitlog and caches, 3 HDDs - data)
1 KS => 1 CF => 1 Colum
Jonathan Ellis gmail.com> writes:
>
> drop and truncate both snapshot first, which requires forking to run
> ln if you don't have JNA installed.
>
> best solution: install JNA so it can do in-process link calls.
>
Could you please tell exact actions in client (or not in client ?) that should
b
Hello.
We have a problem with finding way to store user news list.
Our task - we have 2 group of filters:
1) News Types(photo, video, audio, etc... )
2) User Lists(user, friends, friends friends, etc..)
Our solution ways:
1) Store matrix of filters for each user.
UserNews:
user_id1:
:
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