nodetool cfhistograms is also very helpful in diagnosing these kinds of
data modelling issues.
On 23 March 2015 at 14:43, Chris Lohfink wrote:
>
> >> Compacted partition maximum bytes: 36904729268
>
> thats huge... 36gb rows are gonna cause a lot of problems, even when you
> specify a precise c
>> Compacted partition maximum bytes: 36904729268
thats huge... 36gb rows are gonna cause a lot of problems, even when you
specify a precise cell under this it still is going to have an enormous
column index to deserialize on every read for the partition. As mentioned
above, you should include y
I haven't deleted anything. Here's output from a traced cqlsh query (I
tried to make the spaces line up, hope it's legible):
Execute CQL3
query
| 2015-03-23 21:04:37.422000 | 172.31.32.211 | 0
Parsing select * from default.metrics where row_time = 16511 and attrs =
'[redacted]' limit
Enable tracing in cqlsh and see how many sstables are being lifted to
satisfy the query (are you repeatedly writing to the same partition
[row_time]) over time?).
Also watch for whether you're hitting a lot of tombstones (are you deleting
lots of values in the same partition over time?).
On Mon,
Duncan: I'm thinking it might be something like that. I'm also seeing just
a ton of garbage collection on the box, could it be pulling rows for all
100k attrs for a given row_time into memory since only row_time is the
partition key?
Jens: I'm not using EBS (although I used to until I read up on h
Also, two control questions:
- Are you using EBS for data storage? It might introduce additional
latencies.
- Are you doing proper paging when querying the keyspace?
Cheers,
Jens
On Mon, Mar 23, 2015 at 5:56 AM, Dave Galbraith
wrote:
> Hi! So I've got a table like this:
>
> CREATE TAB
Hi Dave,
On 23/03/15 05:56, Dave Galbraith wrote:
Hi! So I've got a table like this:
CREATE TABLE "default".metrics (row_time int,attrs varchar,offset int,value
double, PRIMARY KEY(row_time, attrs, offset)) WITH COMPACT STORAGE AND
bloom_filter_fp_chance=0.01 AND caching='KEYS_ONLY' AND comment
