Incorrect override of manifest.json?

[Daniel Pyykkö]

Hi all,

In Cassandra 2.1.3 the code below is located in the class 
CassandraFamilyStore.java which is called when you do a snapshot. What I can se 
happens is that it first creates a snapshot manifest file correctly for a 
column family but than the loop returns a index which overrides the data that 
was written in the first iteration. Isn´t the code incorrect and the JSONArray 
should be located before the outer for-loop or some other solution so it does´t 
override content that has once been written?

From the call concatWithIndexes() I see it returns [CFS(Keyspace=’X', 
ColumnFamily='tempState'), CFS(Keyspace=’X', 
ColumnFamily='tempState.tempState_current_idx’)] and the first iteration writes 
correct data to the manifest.json and the second iteration overrides the data 
with a empty filesJSONArr”.

Can somebody please confirm if this is a bug, or if I should write one?


//Kind Regards, Daniel



public void snapshotWithoutFlush(String snapshotName, PredicateSSTableReader 
predicate)
{
for (ColumnFamilyStore cfs : concatWithIndexes())
{
final JSONArray filesJSONArr = new JSONArray();
try (RefViewFragment currentView = 
cfs.selectAndReference(ALL_SSTABLES))
{
for (SSTableReader ssTable : currentView.sstables)
{
if (ssTable.openReason == SSTableReader.OpenReason.EARLY || 
(predicate != null  !predicate.apply(ssTable)))
{
continue;
}

File snapshotDirectory = 
Directories.getSnapshotDirectory(ssTable.descriptor, snapshotName);
ssTable.createLinks(snapshotDirectory.getPath()); // hard 
links

filesJSONArr.add(ssTable.descriptor.relativeFilenameFor(Component.DATA));
if (logger.isDebugEnabled())
logger.debug(Snapshot for {} keyspace data file {} 
created in {}, keyspace, ssTable.getFilename(), snapshotDirectory);
}

writeSnapshotManifest(filesJSONArr, snapshotName);
}
}
}

Re: Incorrect override of manifest.json?

[Robert Coli]

On Thu, Apr 16, 2015 at 6:29 AM, Daniel Pyykkö daniel.pyy...@sitevision.se
wrote:

 In Cassandra 2.1.3 the code below is located in the class
 CassandraFamilyStore.java which is called when you do a snapshot. What I
 can se happens is that it first creates a snapshot manifest file correctly
 for a column family but than the loop returns a index which overrides the
 data that was written in the first iteration. Isn´t the code incorrect and
 the JSONArray should be located before the outer for-loop or some other
 solution so it does´t override content that has once been written?


In general if you can make a plausible case that a bug might exist,
especially if you can point it out in the code, you should inquire in one
of three forums, in (in my non-official understanding) descending order of
preference :

1) issues.apache.org
2) cassandra-dev@ mailing list
3) #cassandra-dev IRC channel
4) this list

=Rob