Right, that's sort of a half-repair: it will repair differences in
replies it got, but it won't doublecheck md5s on the rest in the
background. So if you're doing CL.ONE reads this is a no-op.
On Sat, May 7, 2011 at 4:25 PM, aaron morton wrote:
> I remembered something like that so had a look at
The live:serialized size ratio depends on what your data looks like
(small columns will be less efficient than large blobs) but using the
rule of thumb of 10x, around 1G * (1 + memtable_flush_writers +
memtable_flush_queue_size).
So first thing I would do is drop writers and queue to 1 and 1.
The
I remembered something like that so had a look at
RangeSliceResponseResolver.resolve() in 0.6.12 and it looks like it schedules
the repairs...
protected Row getReduced()
{
ColumnFamily resolved =
ReadResponseResolver.resolveSuperset(versions);
How much memory should a single hot cf with a 128mb memtable take with row and
key caching disabled during read?
Because I'm seeing heap go from 3.5gb skyrocketing straight to max (regardless
of the size, 8gb and 24gb both do the same) at which time the jvm will do
nothing but full gc and is un
I know thrift and python and Unicode don't mix.
On May 7, 2011, at 4:21 PM, aaron morton wrote:
> I've been able to reproduce the fault using python on my mac book see
> https://github.com/amorton/cassandra-unicode-bug
>
> When we try to find the unicode key in the index in 0.7 it fails be
I believe the offset value of Writes and Reads are in *micro*seconds right?
(that page talks about *milli*seconds)
Also, are any timeouts or errors reflected in those times or just successful
operations? if not, is there any JMX or other tool to keep track of them?
Josep M.
On Fri, May 6, 2011
I've been able to reproduce the fault using python on my mac book see
https://github.com/amorton/cassandra-unicode-bug
When we try to find the unicode key in the index in 0.7 it fails because the
tokens are different. The readme in the github project has more info.
Any thoughts? Will try to f
Hi All
some on suggested about linux scheduler cat
/sys/block/sda/queue/scheduler there are quite few of them noop
[anticipatory] deadline cfq.I have changed from cfq default to
anticipatory,Now problem is less for me kswapd0 take 10-50% of cpu in
very short bust less then milliseconds.Also
The only "query planning" Cassandra does is deciding which index to
use when there are multiple options. That is handled the same way
whether the request is from CQL or classic Thrift.
On Sat, May 7, 2011 at 8:17 AM, Edward Capriolo wrote:
> Having used mysql as key value store before I have noti
> It does not really make sense to me to go through all these minor merges
> when a full compaction will do a much faster and better job.
In a system heavily reliant on caching (platter drives, large data
sizes, much larger than RAM) major compactions can be very detrimental
to performance due to
This what free -m and vmstat show now my CPU is on 100%
[root@cassandra2 ~]# free -m
total used free sharedbuffers cached
Mem: 16043 15966 76 0 4900
-/+ buffers/cache: 15061982
Swap:0
This is an all ssd system. I have no problems with read/write performance
due to I/O.
I do have a potential with the crazy explosion you can get in terms of disk
use if compaction cannot keep up.
As things falls behind and you get many generations of data, yes, read
performance gets a problem due
> If you are seeing 600 pending compaction tasks regularly you almost
> definitely need more hardware.
Note that pending compactions is pretty misleading and you can't
really draw conclusions just based on the pending compactions
number/graph. For example, standard behavior during e.g.a long repa
On Sat, May 7, 2011 at 8:54 AM, Jonathan Ellis wrote:
> On Sat, May 7, 2011 at 2:01 AM, Terje Marthinussen
> wrote:
>> 1. Would it make sense to make full compactions occur a bit more aggressive.
>
> I'd rather reduce the performance impact of being behind, than do more
> full compactions: https:
Yes, it is, those last two lines repeat forever:
at
org.apache.tools.ant.PropertyHelper.getPropertyHook(PropertyHelper.java:189)
at
org.apache.maven.artifact.ant.POMPropertyHelper.getPropertyHook(POMPropertyHelper.java:50)
It's trying to look up a property value somewhere and getting
Having used mysql as key value store before I have noticed that when
doing low-latency queries the query planning time can actually end up
being larger then the execution time. Even if you use a prepared
statement mechanism with clients connecting and disconnecting this can
be a lot of overhead. Wi
On Sat, May 7, 2011 at 2:01 AM, Terje Marthinussen
wrote:
> 1. Would it make sense to make full compactions occur a bit more aggressive.
I'd rather reduce the performance impact of being behind, than do more
full compactions: https://issues.apache.org/jira/browse/CASSANDRA-2498
> 2. I
> would th
range_slices respects consistencylevel, but only single-row reads and
multiget do the *repair* part of RR.
On Sat, May 7, 2011 at 1:44 AM, aaron morton wrote:
> get_range_slices() does read repair if enabled (checked
> DoConsistencyChecksBoolean in the config, it's on by default) so you should
I'll quote the top google hit for [kswapd0 100%]:
How much memory did you have in "cached" when you looked
with top (and no swap enabled) ?
If the amount of "cached" memory is very low, it could mean
that your shared libraries are being pushed out of memory,
instead of the kernel swapping out som
Even with the current concurrent compactions, given a high speed datafeed,
compactions will obviously start lagging at some stage, and once it does,
things can turn bad in terms of disk usage and read performance.
I have not read the compaction code well, but if
http://wiki.apache.org/cassandra/Me
get_range_slices() does read repair if enabled (checked
DoConsistencyChecksBoolean in the config, it's on by default) so you should be
getting good reads. If you want belt-and-braces run nodetool repair first.
Hope that helps.
On 7 May 2011, at 11:46, Jeremy Hanna wrote:
> Great! I just wan
Hi That sloved my issue of GC,Now i am facing with new one
i have no swap but this process kswapd0 take up 100% cpu when there is
load on cassandra any idea why this is happening
On 05/05/2011 09:06 PM, Ali Ahsan wrote:
Thanks replying,let me disable my swap memory.
On 05/05/2011 09:01 PM,
vpn on ubuntu should be easy if you ask your good friend google... you
should not have to pay for it (but paying might get you a fancy GUI, or
perhaps very optimized performance that could squeeze a few more %)
- Stephen
---
Sent from my Android phone, so random spelling mistakes, random nonsense
if you can give me (an intellij user) enough details to reproduce on my MBP
I'll try and fix it.
things like, download this eclipse distro, add these update centers, set
these env variables, then clicks through this horrible UI as follows...
presto crash!
- Stephen
---
Sent from my Android phone
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