[jira] [Commented] (CASSANDRA-3943) Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.
[
https://issues.apache.org/jira/browse/CASSANDRA-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13235437#comment-13235437
]
Peter Schuller commented on CASSANDRA-3943:
---
We are working on generating single-range-per-reducer sstables so that there is
no overlap, and each reducer can send to a single node (or at least one node
per sstable generated). It doesn't address local storage, but does address this.
It also has the effect that if we combine it with log(n) filtering of sstables
in the read path based on ranges, it would be feasable to bulk import and have
thousands of sstables and completely disable compaction.
> Too many small size sstables after loading data using sstableloader or
> BulkOutputFormat increases compaction time.
> --
>
> Key: CASSANDRA-3943
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3943
> Project: Cassandra
> Issue Type: Wish
> Components: Hadoop, Tools
>Affects Versions: 0.8.2, 1.1.0
>Reporter: Samarth Gahire
>Priority: Minor
> Labels: bulkloader, hadoop, ponies, sstableloader, streaming,
> tools
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> When we create sstables using SimpleUnsortedWriter or BulkOutputFormat,the
> size of sstables created is around the buffer size provided.
> But After loading , sstables created in the cluster nodes are of size around
> {code}( (sstable_size_before_loading) * replication_factor ) /
> No_Of_Nodes_In_Cluster{code}
> As the no of nodes in cluster goes increasing, size of each sstable loaded to
> cassandra node decreases.Such small size sstables take too much time to
> compact (minor compaction) as compare to relatively large size sstables.
> One solution that we have tried is to increase the buffer size while
> generating sstables.But as we increase the buffer size ,time taken to
> generate sstables increases.Is there any solution to this in existing
> versions or are you fixing this in future version?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CASSANDRA-3943) Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.
[
https://issues.apache.org/jira/browse/CASSANDRA-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13235440#comment-13235440
]
Peter Schuller commented on CASSANDRA-3943:
---
It also facilitates replacing a data set one sstable at a time (if one
generates sstables that correspond exactly in ranges), allowing completely
replacement of a dataset without a temporary disk space spike.
Without any of these fixes, extra disk space needed is very significant - both
regular compaction overhead in addition to loading two data sets onto the node.
> Too many small size sstables after loading data using sstableloader or
> BulkOutputFormat increases compaction time.
> --
>
> Key: CASSANDRA-3943
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3943
> Project: Cassandra
> Issue Type: Wish
> Components: Hadoop, Tools
>Affects Versions: 0.8.2, 1.1.0
>Reporter: Samarth Gahire
>Priority: Minor
> Labels: bulkloader, hadoop, ponies, sstableloader, streaming,
> tools
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> When we create sstables using SimpleUnsortedWriter or BulkOutputFormat,the
> size of sstables created is around the buffer size provided.
> But After loading , sstables created in the cluster nodes are of size around
> {code}( (sstable_size_before_loading) * replication_factor ) /
> No_Of_Nodes_In_Cluster{code}
> As the no of nodes in cluster goes increasing, size of each sstable loaded to
> cassandra node decreases.Such small size sstables take too much time to
> compact (minor compaction) as compare to relatively large size sstables.
> One solution that we have tried is to increase the buffer size while
> generating sstables.But as we increase the buffer size ,time taken to
> generate sstables increases.Is there any solution to this in existing
> versions or are you fixing this in future version?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CASSANDRA-3943) Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.
[
https://issues.apache.org/jira/browse/CASSANDRA-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13235427#comment-13235427
]
Stu Hood commented on CASSANDRA-3943:
-
I'd like to work on this, as it seems like it should be possible to make a
BulkOutputFormat that writes at most one sstable from each reducer to each
host, if you sort the data by token before it arrives at the reducer.
Essentially, the OutputFormat would assert that it was receiving the data in
sorted order, and write it straight to the socket as an sstable data file: this
has been the 'lifelong dream' of MapReduce integration.
> Too many small size sstables after loading data using sstableloader or
> BulkOutputFormat increases compaction time.
> --
>
> Key: CASSANDRA-3943
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3943
> Project: Cassandra
> Issue Type: Wish
> Components: Hadoop, Tools
>Affects Versions: 0.8.2, 1.1.0
>Reporter: Samarth Gahire
>Priority: Minor
> Labels: bulkloader, hadoop, ponies, sstableloader, streaming,
> tools
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> When we create sstables using SimpleUnsortedWriter or BulkOutputFormat,the
> size of sstables created is around the buffer size provided.
> But After loading , sstables created in the cluster nodes are of size around
> {code}( (sstable_size_before_loading) * replication_factor ) /
> No_Of_Nodes_In_Cluster{code}
> As the no of nodes in cluster goes increasing, size of each sstable loaded to
> cassandra node decreases.Such small size sstables take too much time to
> compact (minor compaction) as compare to relatively large size sstables.
> One solution that we have tried is to increase the buffer size while
> generating sstables.But as we increase the buffer size ,time taken to
> generate sstables increases.Is there any solution to this in existing
> versions or are you fixing this in future version?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CASSANDRA-3943) Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.
[
https://issues.apache.org/jira/browse/CASSANDRA-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13214808#comment-13214808
]
Brandon Williams commented on CASSANDRA-3943:
-
bq. As the no of nodes in cluster goes increasing, size of each sstable loaded
to cassandra node decreases
This is unavoidable, since the sstable now contains more ranges that belong to
specific replica ranges in the ring.
bq. Such small size sstables take too much time to compact (minor compaction)
Assuming SizeTieredStrategy, increasing the maximum threshold may help this to
some degree, so that the nodes compact more tiny sstables at a time.
bq. Is there any solution to this in existing versions or are you fixing this
in future version?
I'm open to ideas, but have no plans as there is no clear solution.
> Too many small size sstables after loading data using sstableloader or
> BulkOutputFormat increases compaction time.
> --
>
> Key: CASSANDRA-3943
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3943
> Project: Cassandra
> Issue Type: Improvement
> Components: Hadoop, Tools
>Affects Versions: 0.8.2, 1.1.0
>Reporter: Samarth Gahire
>Assignee: Brandon Williams
>Priority: Minor
> Labels: bulkloader, hadoop, sstableloader, streaming, tools
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> When we create sstables using SimpleUnsortedWriter or BulkOutputFormat,the
> size of sstables created is around the buffer size provided.
> But After loading , sstables created in the cluster nodes are of size around
> {code}( (sstable_size_before_loading) * replication_factor ) /
> No_Of_Nodes_In_Cluster{code}
> As the no of nodes in cluster goes increasing, size of each sstable loaded to
> cassandra node decreases.Such small size sstables take too much time to
> compact (minor compaction) as compare to relatively large size sstables.
> One solution that we have tried is to increase the buffer size while
> generating sstables.But as we increase the buffer size ,time taken to
> generate sstables increases.Is there any solution to this in existing
> versions or are you fixing this in future version?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
