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https://issues.apache.org/jira/browse/CASSANDRA-4340?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13406206#comment-13406206
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Pavel Yaskevich commented on CASSANDRA-4340:
--------------------------------------------
Ivan, is everything alright after rebuild of the CF after a work day?
> Cassandra upgrade to 1.1.1 resulted in slow query issue
> -------------------------------------------------------
>
> Key: CASSANDRA-4340
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4340
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.1.1
> Environment: Ubuntu Linux, Java 7, Hector 1.0-1
> Reporter: Ivan Ganza
> Assignee: Pavel Yaskevich
> Fix For: 1.1.3
>
> Attachments: CassandraIssue.java
>
>
> We have recently introduced Cassandra at the Globe and Mail here in Toronto,
> Canada. We are processing and storing the North American stock-market feed.
> We have found it to work very quickly and things have been looking very good.
> Recently we upgraded to version 1.1.1 and then we have noticed some issues
> occurring.
> I will try to describe it for you here. Basically one operation that we very
> often perform and is very critical is the ability to 'get the latest quote'.
> This would return to you the latest Quote adjusted against exchange delay
> rules. With Cassandra version 1.0.3 we could get a Quote in around 2ms.
> After update we are looking at time of at least 2-3 seconds.
> The way we query the quote is using a REVERSED SuperSliceQuery with
> start=now, end=00:00:00.000 (beginning of day) LIMITED to 1.
> Our investigation leads us to suspect that, since upgrade, Cassandra seems to
> be reading the sstable from disk even when we request a small range of day
> only 5 seconds back. If you look at the output below you can see that the
> query does NOT get slower as the lookback increases from 5 sec, 60 sec, 15
> min, 60 min, and 24 hours.
> We also noticed that the query was very fast for the first five minutes of
> trading, apparently until the first sstable was flushed to disk. After that
> we go into query times of 1-2 seconds or so.
> Query time[lookback=5]:[1711ms]
> Query time[lookback=60]:[1592ms]
> Query time[lookback=900]:[1520ms]
> Query time[lookback=3600]:[1294ms]
> Query time[lookback=86400]:[1391ms]
> We would really appreciate input or help on this.
> Cassandra version: 1.1.1
> Hector version: 1.0-1
> ---
> public void testCassandraIssue() {
> try {
> int[] seconds = new int[]{ 5, 60, 60 * 15, 60 * 60, 60 * 60
> * 24};
> for(int sec : seconds) {
> DateTime start = new DateTime();
> SuperSliceQuery<String, String, String, String>
> superSliceQuery = HFactory.createSuperSliceQuery(keyspaceOperator,
> StringSerializer.get(), StringSerializer.get(), StringSerializer.get(),
> StringSerializer.get());
> superSliceQuery.setKey("101390" + "." +
> testFormatter.print(start));
> superSliceQuery.setColumnFamily("Quotes");
>
> superSliceQuery.setRange(superKeyFormatter.print(start),
>
> superKeyFormatter.print(start.minusSeconds(sec)),
> true,
> 1);
> long theStart = System.currentTimeMillis();
> QueryResult<SuperSlice<String, String, String>>
> result = superSliceQuery.execute();
> long end = System.currentTimeMillis();
> System.out.println("Query time[lookback=" + sec +
> "]:[" + (end - theStart) + "ms]");
> }
> } catch(Exception e) {
> e.printStackTrace();
> fail(e.getMessage());
> }
> }
> ---
> create column family Quotes
> with column_type = Super
> and comparator = BytesType
> and subcomparator = BytesType
> and keys_cached = 7000
> and rows_cached = 0
> and row_cache_save_period = 0
> and key_cache_save_period = 3600
> and memtable_throughput = 255
> and memtable_operations = 0.29
> AND compression_options={sstable_compression:SnappyCompressor,
> chunk_length_kb:64};
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