@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Subject: Re: Hot, large row
Is it the accumulated tombstones on a row that make it act as if “wide”? Does
cfhistograms count the tombstones or subtract them when reporting on cell-count
for rows? (I don’t know.)
-- Jack Krupansky
Fr
: Don Jackson
Subject: Re: Hot, large row
Ha, check out who filed that ticket! Yes I’m aware of it. My hope is that it
was mostly addressed in CASSANDRA-6563 so I may upgrade from 2.0.6 to 2.0.9.
I’m really just surprised that others are not doing similar actions as I and
thus experiencing
gt;"
mailto:user@cassandra.apache.org>>
Date: Friday, July 25, 2014 at 10:06 AM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Cc: Don Jackson mailto:djack...@nanigans.com>>
Subject: Re: Hot, large row
https://issues.apache.org/jira/browse/CASSANDRA-6654
ue?
>
> I am hoping to upgrade to 2.0.9 which has improvements to remove
> tombstones.
>
> From: Keith Wright
> Reply-To: "user@cassandra.apache.org"
> Date: Thursday, July 24, 2014 at 4:50 PM
> To: "user@cassandra.apache.org"
> Cc: Don Jackson
>
&g
Hello Keith
1. Periodically seeing one node stuck in CMS GC causing high read
latency. Seems to recover on its own after an hour or so
How many nodes do you have ? And how many distinct user_id roughtly is
there ?
Looking at your jvm settings it seems that you have the GC log enabled. It
Hi Keith,
On 25/07/14 14:43, Keith Wright wrote:
Answers to your questions below but in the end I believe the root issue here is
that LCS is clearly not compacting away as it should resulting in reads across
many SSTables which as you noted is “fishy”. I’m considering filing a JIRA for
this, s
@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Subject: Re: Hot, large row
What are your jvm settings?
Your read pattern implies that you may fetch lots of data into memory (reading
all skus for a given user), maybe it stressed too much the jvm.
emove
> tombstones.
>
> From: Keith Wright
> Reply-To: "user@cassandra.apache.org"
> Date: Thursday, July 24, 2014 at 4:50 PM
> To: "user@cassandra.apache.org"
> Cc: Don Jackson
> Subject: Re: Hot, large row
>
> When a node is showing the high CMS
gt;>
Date: Thursday, July 24, 2014 at 4:50 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Cc: Don Jackson mailto:djack...@nanigans.com>>
Subject: Re: Hot, large row
When a node is showing the high CMS issue, io is
rsday, July 24, 2014 at 4:44 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Subject: Re: Hot, large row
For global_user_event_skus_v2
1. number of SSTables per read is quite huge. Considering you're using LCS, i
1597 us: 177538
>
>1916 us: 169568
>
>2299 us: 177617
>
>2759 us: 202552
>
>3311 us: 198101
>
>3973 us: 179807
>
>4768 us: 159149
>
>5722 us: 142282
>
>6866 us: 126124
>
>8239 us: 111529
>
>9887
cells: 48
642 cells: 25
770 cells: 9
924 cells: 9
1109 cells: 4
1331 cells: 3
1597 cells: 1
1916 cells: 2
From: Jack Krupansky mailto:j...@basetechnology.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org&g
?
-- Jack Krupansky
From: DuyHai Doan
Sent: Thursday, July 24, 2014 3:53 PM
To: user@cassandra.apache.org
Subject: Re: Hot, large row
Your extract of cfhistograms show that there are no particular "wide rows". The
widest has 61214 cells which is big but not that huge to be really
e a
> large row? If it were a small row being called repeatedly, I assume OS/key
> cache would make that a VERY fast operation.
>
> Thanks
>
> From: DuyHai Doan
> Reply-To: "user@cassandra.apache.org"
> Date: Thursday, July 24, 2014 at 3:53 PM
>
> To: "u
lt;mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Date: Thursday, July 24, 2014 at 3:53 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Subject: Re: Hot, large row
Your extract of cf
8
>
> 1916 cells: 773
>
> 2299 cells: 495
>
> 2759 cells: 268
>
> 3311 cells: 150
>
> 3973 cells: 100
>
> 4768 cells: 42
>
> 5722 cells: 24
>
> 6866 cells: 12
>
> 8239 cells: 9
>
> 9887 cells: 3
>
> 11864 ce
e.org>>
Date: Thursday, July 24, 2014 at 3:01 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
mailto:user@cassandra.apache.org>>
Subject: Re: Hot, large row
"How can I detect wide rows?" -->
nodetool cfhistograms
Look at column "
"How can I detect wide rows?" -->
nodetool cfhistograms
Look at column "Column count" (last column) and identify a line in this
column with very high value of "Offset". In a well designed application you
should have a gaussian distribution where 80% of your row have a similar
number of columns.
Hi all,
We are seeing an issue where basically daily one of our nodes spikes in load
and is churning in CMS heap pressure. It appears that reads are backing up and
my guess is that our application is reading a large row repeatedly. Our write
structure can lead itself to wide rows very infr
19 matches
Mail list logo
