Yup, that would be expected.
Remember that doing `scan -c ...` is an unbounded search over your
entire table. So, it takes approximately 3 minutes to read your
GUIDIndexTable. Because you have a single locality group, all of the
columns in your table are grouped together.
One exercise that may be interesting for yourself is to create a
locality group that has your specific column family in it, compact your
GUIDIndexTable, and rerun your `scan -c` query. The speed should be
similar to your exact scan. Removing the locality group and
re-compacting the table should return the query time back to the slow 3
minutes.
Does that make sense?
Daniel Ruiz wrote:
Hi All,
I am having an issue where column fetches are taking over a minute on
1.6.3. I don’t believe this should be case and my experience in the past
supports the idea that fetches should be very fast.
For example we doing a scan on the table gives results instantly but
doing a scan -c vesselmmsitext=2706758566 takes 2 minutes and 44 seconds
(plus or minus 1 second).
Figure 1.1. Generated Test Data on GUIDIndexTable
Here is the table config
-----------+---------------------------------------------------------------+---------------------------------------------------------------------------------
SCOPE | NAME | VALUE
-----------+---------------------------------------------------------------+---------------------------------------------------------------------------------
default | table.balancer ..............................................
| org.apache.accumulo.server.master.balancer.DefaultLoadBalancer
default | table.bloom.enabled .........................................
| false
default | table.bloom.error.rate ......................................
| 0.5%
default | table.bloom.hash.type .......................................
| murmur
default | table.bloom.key.functor .....................................
| org.apache.accumulo.core.file.keyfunctor.RowFunctor
default | table.bloom.load.threshold .................................. | 1
default | table.bloom.size ............................................
| 1048576
default | table.cache.block.enable ....................................
| false
default | table.cache.index.enable ....................................
| true
default | table.classpath.context ..................................... |
default | table.compaction.major.everything.idle ...................... | 1h
default | table.compaction.major.ratio ................................ | 3
default | table.compaction.minor.idle ................................. | 5m
default | table.compaction.minor.logs.threshold ....................... | 3
table | table.constraint.1 .......................................... |
org.apache.accumulo.core.constraints.DefaultKeySizeConstraint
default | table.failures.ignore .......................................
| false
default | table.file.blocksize ........................................ | 0B
default | table.file.compress.blocksize ...............................
| 100K
default | table.file.compress.blocksize.index .........................
| 128K
default | table.file.compress.type .................................... | gz
default | table.file.max .............................................. | 15
default | table.file.replication ...................................... | 0
default | table.file.type ............................................. | rf
default | table.formatter .............................................
| org.apache.accumulo.core.util.format.DefaultFormatter
default | table.groups.enabled ........................................ |
default | table.interepreter ..........................................
| org.apache.accumulo.core.util.interpret.DefaultScanInterpreter
table | table.iterator.majc.AgeOffIterator##GUIDIndexTable .......... |
1,org.apache.accumulo.core.iterators.user.AgeOffFilter
table | table.iterator.majc.AgeOffIterator##GUIDIndexTable.opt.ttl .. |
2592000000
table | table.iterator.majc.vers .................................... |
20,org.apache.accumulo.core.iterators.user.VersioningIterator
table | table.iterator.majc.vers.opt.maxVersions .................... | 1
table | table.iterator.minc.AgeOffIterator##GUIDIndexTable .......... |
1,org.apache.accumulo.core.iterators.user.AgeOffFilter
table | table.iterator.minc.AgeOffIterator##GUIDIndexTable.opt.ttl .. |
2592000000
table | table.iterator.minc.vers .................................... |
20,org.apache.accumulo.core.iterators.user.VersioningIterator
table | table.iterator.minc.vers.opt.maxVersions .................... | 1
table | table.iterator.scan.AgeOffIterator##GUIDIndexTable .......... |
1,org.apache.accumulo.core.iterators.user.AgeOffFilter
table | table.iterator.scan.AgeOffIterator##GUIDIndexTable.opt.ttl .. |
2592000000
---------------------------------------------------------- hit any key
to continue or 'q' to quit
----------------------------------------------------------
table | table.iterator.scan.vers .................................... |
20,org.apache.accumulo.core.iterators.user.VersioningIterator
table | table.iterator.scan.vers.opt.maxVersions .................... | 1
default | table.majc.compaction.strategy ..............................
| org.apache.accumulo.tserver.compaction.DefaultCompactionStrategy
default | table.scan.max.memory .......................................
| 512K
table | @override ................................................ | 1M
default | table.security.scan.visibility.default ...................... |
default | table.split.threshold ....................................... | 1G
default | table.walog.enabled .........................................
| true
-----------+---------------------------------------------------------------+---------------------------------------------------------------------------------
More Table Info:
GUIDIndexTable <http://107.23.12.24:50095/tables?t=f>
ONLINE
2
0
82.56M
810.00K
159
Please let me know if I am doing something wrong to if there is more
information you need.
V/r,
-Daniel
