[
https://issues.apache.org/jira/browse/HBASE-1823?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12754364#action_12754364
]
Jonathan Gray commented on HBASE-1823:
--------------------------------------
Hmm... now when running with addition to the Writable, I get this exception:
{noformat}
2009-09-11 13:14:03,903 WARN org.apache.hadoop.hbase.master.BaseScanner: Scan
ROOT region
java.io.IOException: Call to /192.168.249.102:61020 failed on local exception:
java.io.EOFException
at
org.apache.hadoop.hbase.ipc.HBaseClient.wrapException(HBaseClient.java:757)
at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:727)
at
org.apache.hadoop.hbase.ipc.HBaseRPC$Invoker.invoke(HBaseRPC.java:328)
at $Proxy1.openScanner(Unknown Source)
at
org.apache.hadoop.hbase.master.BaseScanner.scanRegion(BaseScanner.java:160)
at
org.apache.hadoop.hbase.master.RootScanner.scanRoot(RootScanner.java:54)
at
org.apache.hadoop.hbase.master.RootScanner.initialScan(RootScanner.java:73)
at
org.apache.hadoop.hbase.master.BaseScanner.initialChore(BaseScanner.java:131)
at org.apache.hadoop.hbase.Chore.run(Chore.java:66)
Caused by: java.io.EOFException
at java.io.DataInputStream.readInt(DataInputStream.java:375)
at
org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:505)
at
org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:449)
{noformat}
The code seems right... what am I missing here?
{noformat}
@@ -518,6 +545,7 @@
this.stopRow = Bytes.readByteArray(in);
this.maxVersions = in.readInt();
this.caching = in.readInt();
+ this.cacheBlocks = in.readBoolean();
if(in.readBoolean()) {
this.filter =
(Filter)createForName(Bytes.toString(Bytes.readByteArray(in)));
this.filter.readFields(in);
@@ -550,6 +578,7 @@
Bytes.writeByteArray(out, this.stopRow);
out.writeInt(this.maxVersions);
out.writeInt(this.caching);
+ out.writeBoolean(this.cacheBlocks);
if(this.filter == null) {
out.writeBoolean(false);
} else {
{noformat}
> Ability for Scanners to bypass the block cache
> ----------------------------------------------
>
> Key: HBASE-1823
> URL: https://issues.apache.org/jira/browse/HBASE-1823
> Project: Hadoop HBase
> Issue Type: New Feature
> Components: client, regionserver
> Affects Versions: 0.20.0
> Reporter: Jonathan Gray
> Assignee: Jonathan Gray
> Fix For: 0.20.1, 0.21.0
>
> Attachments: HBASE-1823-v1.patch, HBASE-1823-v2.patch,
> HBASE-1823-v3.patch
>
>
> There are a number of use cases where exposing the ability to not cache
> blocks during a scan would be valuable. For example, running row counts.
> The LRU is scan-resistant, so it does provide some protection already, but
> even in that case all you prevent is the eviction of hot blocks. The LRU
> still runs many evictions and the blocks are referenced for much longer
> periods of time, so this adds enormous stress to the GC.
> Compactions already do this. This issue is about exposing that as a switch
> to the client-side Scan object (will also enable it for MR jobs then).
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
