1. i download the src code from:
http://mirrors.hust.edu.cn/apache/hbase/0.98.15/
class: org.apache.hadoop.hbase.master.snapshot.SnapshotManager
method: public void restoreSnapshot(SnapshotDescription reqSnapshot)
throws IOException
line: 725
code:
if (cpHost != null) {
cpHost.postRestoreSnapshot(reqSnapshot, snapshotTableDesc);
}
} else {
HTableDescriptor htd =
RestoreSnapshotHelper.cloneTableSchema(snapshotTableDesc, tableName);
if (cpHost != null) {
cpHost.preCloneSnapshot(reqSnapshot, htd);
}
cloneSnapshot(fsSnapshot, htd);
LOG.info("Clone snapshot=" + fsSnapshot.getName() + " as table=" +
tableName);
if (cpHost != null) {
cpHost.postCloneSnapshot(reqSnapshot, htd);
}
i think the clone:
HTableDescriptor htd =
RestoreSnapshotHelper.cloneTableSchema(snapshotTableDesc, tableName);
can be removed.
2. this one is similar to the one in HBaseAdmin.getTableDecsriptor
3. add method 'isSnapShotExists' in HBaseAdmin to help us to know if there is
a snopshot on HDFS, just like HBaseAdmin.tableExists,
before we create a snopshot of a table, we can check if there is a snopshot
with same name
4. simplify the code
version: hbase 0.98.15
class: org.apache.hadoop.hbase.master.cleaner.CleanerChore
method:private boolean checkAndDeleteFiles(List<FileStatus> files)
line: 235-243
code:
// trace which cleaner is holding on to each file
if (LOG.isTraceEnabled()) {
ImmutableSet<FileStatus> filteredFileSet =
ImmutableSet.copyOf(filteredFiles);
for (FileStatus file : deletableValidFiles) {
if (!filteredFileSet.contains(file)) {
LOG.trace(file.getPath() + " is not deletable according to:" +
cleaner);
}
}
}
i think these code can use set's difference operation instead, which is
more straightforward
At 2015-11-07 21:10:21, "Ted Yu" <[email protected]> wrote:
>For #1, I took a look at current 0.98 code but didn't find it.
>Can you double check and tell us the updated line number ?
>
>For #2, I think it makes sense - considering there may be large number of
>snapshots in the cluster.
>
>For #3, can you tell us the use case for the new API ?
>
>Cheers
>
>On Fri, Nov 6, 2015 at 10:12 PM, 王勇强 <[email protected]> wrote:
>
>> the version is hbase0.98.10, find some improvements on snapshot:
>> 1. in class SnapshotManager, line 725, we make a clone of
>> HTableDescriptor, the clone is not so need to make
>> 2 class HBaseAdmin, method
>> public void restoreSnapshot(final String snapshotName, boolean
>> takeFailSafeSnapshot)
>> {
>> TableName tableName = null;
>> for (SnapshotDescription snapshotInfo: listSnapshots()) {
>> if (snapshotInfo.getName().equals(snapshotName)) {
>> tableName = TableName.valueOf(snapshotInfo.getTable());
>> break;
>> }
>> }
>> ......
>> }
>> must get all snapshot from master and then get the one we need, can
>> improve this, master just return the snapshot client needed
>>
>>
>> 3. there should better has a method 'isSnapShotExists' in HBaseAdmin
>>
>>
>>
>>
>>
>>
>>
>>
