On Mon, Apr 20, 2015 at 8:09 PM, Dikang Gu dikan...@gmail.com wrote:
Why do you say steaming is single threaded? I see a lot of background
streaming threads running, for example:
Imprecise :
Each stream is a single thread.
As I said, first place to look is throttles... but I would not be
Thanks Brice!!
We are using Red Hat Linux 6.4..24 cores...64Gb Ram..SSDs in RAID5..CPU are not
overloaded even in peak load..I dont think IO is an issue as iostat shows
await17 all times..util attrbute in iostat usually increases from 0 to
100..and comes back immediately..m not an expert on
Whats ur sstable count for the CF? I hope compactions are working fine. Also
check the full stacktrace of FileNotFoundException ..if its related to
compactionyou can try cleaning compactions_in_progress folder in system
folder in data directory..there are JIRA issues relating to that.
sorry i take that back we will modify different keys across threads not the
same key, our storm topology is going to use field grouping to get updates
for same keys to same set of bolts.
On Tue, Apr 21, 2015 at 6:17 PM, Anishek Agarwal anis...@gmail.com wrote:
@Bruice : I dont think so as i am
@Bruice : I dont think so as i am giving each thread a specific key range
with no overlaps this does not seem to be the case now. However we will
have to test where we have to modify the same key across threads -- do u
think that will cause a problem ? As far as i have read LCS is recommended
for
I’m not sure I get everything about storm stuff, but my understanding of
LCS is that compaction count may increase the more one update data (that’s
why I was wondering about duplicate primary keys).
Another option is that the code is sending too much write request/s to the
cassandra cluster. I
We were chatting to Jon Haddena about a week ago about our tombstone issue
using Cassandra 2.0.14
To Summarize
We have a 3 node cluster with replication-factor=3 and compaction = SizeTiered
We use 1 keyspace with 1 table
Each row have about 40 columns
Each row has a TTL of 10 seconds
We insert
Any suggestions or comments on this one??
Thanks
Anuj Wadhera
Sent from Yahoo Mail on Android
From:Anuj Wadehra anujw_2...@yahoo.co.in
Date:Mon, 20 Apr, 2015 at 11:51 pm
Subject:Re: Handle Write Heavy Loads in Cassandra 2.0.3
Small correction: we are making writes in 5 cf an reading frm
If you never delete except by ttl, and always write with the same ttl (or
monotonically increasing), you can set gc_grace_seconds to 0.
That's what we do. There have been discussions on the list over the last
few years re this topic.
ml
On Tue, Apr 21, 2015 at 11:14 AM, Walsh, Stephen
Are you on version 2.1.x?
Regards,
Carlos Juzarte Rolo
Cassandra Consultant
Pythian - Love your data
rolo@pythian | Twitter: cjrolo | Linkedin: *linkedin.com/in/carlosjuzarterolo
http://linkedin.com/in/carlosjuzarterolo*
Mobile: +31 6 159 61 814 | Tel: +1 613 565 8696 x1649
www.pythian.com
On
Thanks everyone for the suggestions!
I have used the following code to create my cluster from my dev environment
and it seems to be working perfectly:
cluster = Cluster.*builder*
().addContactPoints(nodes).withAddressTranslater(*new* AddressTranslater() {
Could it that the app is inserting _duplicate_ keys ?
-- Brice
On Tue, Apr 21, 2015 at 1:52 PM, Marcus Eriksson krum...@gmail.com wrote:
nope, but you can correlate I guess, tools/bin/sstablemetadata gives you
sstable level information
and, it is also likely that since you get so many L0
Maybe thanks Michael,
I will give these setting a go,
How do you do you periodic node-tool repairs in the situation, for what I read
we need to start doing this also.
https://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repair
From: Laing, Michael
Discussions previously on the list show why this is not a problem in much
more detail.
If something changes in your cluster: node down, new node, etc - you run
repair for sure.
We also run periodic repairs prophylactically.
But if you never delete and always ttl by the same amount, you do not
Hi guys,
We have some issues with streaming in 2.1.2. We find that there are a lot
of patches in 2.1.5. Is it ready for upgrade?
Thanks.
--
Dikang
Robert,
Can you elaborate more please?
Cheers,
Brian
On Tuesday, April 21, 2015, Robert Coli rc...@eventbrite.com wrote:
On Tue, Apr 21, 2015 at 2:25 PM, Dikang Gu dikan...@gmail.com
javascript:_e(%7B%7D,'cvml','dikan...@gmail.com'); wrote:
We have some issues with streaming in 2.1.2. We
Hi,
I am trying to build a project the source bundled downloaded from
http://apache.arvixe.com/cassandra/2.1.4/apache-cassandra-2.1.4-src.tar.gz
but when I run ant build I get following error during build. Any idea why
I am getting build Failed? Seems looking for dependencies
I want to draw a distinction between a) multithreaded compaction (the jira
I just pointed to) and b) concurrent_compactors. I'm not clear on which one
you are recommending at this stage.
a) Multithreaded compaction is what I warned against in my last note. b)
Concurrent compactors is the number
Do not enable multithreaded compaction. Overhead usually outweighs any
benefit. It's removed in 2.1 because it harms more than helps:
https://issues.apache.org/jira/browse/CASSANDRA-6142
All the best,
[image: datastax_logo.png] http://www.datastax.com/
Sebastián Estévez
Solutions Architect |
Hi, I cannot really answer your question as some rock solid truth.
When we had problems, we did mainly two things
- Analyzed the GC logs (with censum from jClarity, this tool IS really
awesome, it’s good investment even better if the production is running
other java applications)
-
Hi,
While setting up a cluster for our POC, when we installed Cassandra on the 1st
node we gave num_tokens: 256 , while on next 2 nodes which were added later we
left it blank in Cassandra.yaml.
This made our cluster an unbalanced one with nodetool status showing 99% load
on one server. Now
Thanks Brice for the input,
I am confused as to how to calculate the value of concurrent_read,
following is what i found recommended on sites and in configuration docs.
concurrent_read : some places its 16 X number of drives or 4 X number of
cores
which of the above should i pick ? i have 40
Yes I was referring referring to multithreaded_compaction, but just because
we didn’t get bitten by this setting just doesn’t mean it’s right, and the
jira is a clear indication of that ;)
@Anishek that reminds me of these settings to look at as well:
- concurrent_write and concurrent_read
@Marcus I did look and that is where i got the above but it doesnt show any
detail about moving from L0 -L1 any specific arguments i should try with ?
On Tue, Apr 21, 2015 at 4:52 PM, Marcus Eriksson krum...@gmail.com wrote:
you need to look at nodetool compactionstats - there is probably a big
Hello,
We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
writer test (written in java) that runs 50 threads to populate data to a
single table in a single keyspace.
when i look at the iftop I see that the amount of network transfer
happening on two nodes is same but on one
nope, but you can correlate I guess, tools/bin/sstablemetadata gives you
sstable level information
and, it is also likely that since you get so many L0 sstables, you will be
doing size tiered compaction in L0 for a while.
On Tue, Apr 21, 2015 at 1:40 PM, Anishek Agarwal anis...@gmail.com wrote:
the some_bits column has about 14-15 bytes of data per key.
On Tue, Apr 21, 2015 at 4:34 PM, Anishek Agarwal anis...@gmail.com wrote:
Hello,
I am inserting about 100 million entries via datastax-java driver to a
cassandra cluster of 3 nodes.
Table structure is as
create keyspace test
you need to look at nodetool compactionstats - there is probably a big L0
- L1 compaction going on that blocks other compactions from starting
On Tue, Apr 21, 2015 at 1:06 PM, Anishek Agarwal anis...@gmail.com wrote:
the some_bits column has about 14-15 bytes of data per key.
On Tue, Apr 21,
Hello,
I am inserting about 100 million entries via datastax-java driver to a
cassandra cluster of 3 nodes.
Table structure is as
create keyspace test with replication = {'class':
'NetworkTopologyStrategy', 'DC' : 3};
CREATE TABLE test_bits(id bigint primary key , some_bits text) with
I am on version 2.0.14, will update once i get the stats up for the writes
again
On Tue, Apr 21, 2015 at 4:46 PM, Carlos Rolo r...@pythian.com wrote:
Are you on version 2.1.x?
Regards,
Carlos Juzarte Rolo
Cassandra Consultant
Pythian - Love your data
rolo@pythian | Twitter: cjrolo |
Hmm - we read/write with Local Quorum always - I'd recommend that as that
is your 'consistency' defense.
We use python, so I am not familiar with the java driver - but 'file not
found' indicates something is inconsistent.
On Tue, Apr 21, 2015 at 12:22 PM, Walsh, Stephen stephen.wa...@aspect.com
This is an intricate matter, I cannot say for sure what are good parameters
from the wrong ones, too many things changed at once.
However there’s many things to consider
- What is your OS ?
- Do your nodes have SSDs or mechanical drives ? How many cores do you
have ?
- Is it the CPUs
On Mon, Apr 20, 2015 at 4:02 PM, Sachin Nikam skni...@gmail.com wrote:
#1. We have 2 data centers located close by with plans to expand to more
data centers which are even further away geographically.
#2. How will this impact light weight transactions when there is high
level of network
On Tue, Apr 21, 2015 at 2:25 PM, Dikang Gu dikan...@gmail.com wrote:
We have some issues with streaming in 2.1.2. We find that there are a lot
of patches in 2.1.5. Is it ready for upgrade?
I personally would not run either version in production at this time, but
if forced, would prefer 2.1.5
Oh, thank you Sebastian for this input and the ticket reference !
We did notice an increase in CPU usage, but kept the concurrent compaction
low enough for our usage, by default it takes the number of cores. We did
use a number up to 30% of our available cores. But under heavy load clearly
CPU is
Thanks for all your help Michael,
Our data will change through the day, so data with a TTL will eventually get
dropped, and new data will appear.
I’d imagine the entire table maybe expire and start over 7-10 times a day.
But on the GC topic, now java Driver now gives this error on the query
I
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