Re: write time for nulls is not consistent

[Jeff Jirsa]

This doesn't reproduce with the steps you're providing. There's clearly some 
pre-existing data in the table, and some sort of operation on that table in the 
past that isn't evident from your repro steps. 

(oss-ccm) MacBook-Pro:~ jjirsa$ ccm create test -n 1 -s -v 3.0.10
Current cluster is now: test
(oss-ccm) MacBook-Pro:~ jjirsa$ ccm node1 cqlsh
Connected to test at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.0.10 | CQL spec 3.4.0 | Native protocol v4]
Use HELP for help.
cqlsh> CREATE KEYSPACE test WITH replication = {'class':'SimpleStrategy', 
'replication_factor': 1};
cqlsh> CREATE TABLE test.t ( a text primary key, b text );
cqlsh> insert into test.t(a) values('z');
cqlsh> insert into test.t(a) values('w');
cqlsh> insert into test.t(a) values('e');
cqlsh> insert into test.t(a) values('r');
cqlsh> insert into test.t(a) values('t');
cqlsh> select a,b, writetime (b) from test.t;

 a | b| writetime(b)
---+--+--
 z | null | null
 e | null | null
 r | null | null
 w | null | null
 t | null | null

(5 rows)
cqlsh>

Are you able to post the json for that table somewhere (sstabledump the 
-Data.db files on disk ) ? 

- Jeff

On 2017-07-19 08:33 (-0700), Nitan Kainth  wrote: 
> Same output Kurt,
> 
> [cqlsh 5.0.1 | Cassandra 3.0.10.1443 | DSE 5.0.4 | CQL spec 3.4.0 | Native 
> protocol v4]
> Use HELP for help.
> cqlsh> select a, writetime(b) from test.t;
> 
>  a | writetime(b)
> ---+--
>  z | null
>  a | null
>  c | null
>  e | null
>  r | null
>  d | 1500400745074499
>  w | 1500400745074499
>  v | 1500400745074499
>  t | 1500400745074499
>  x | 1500400626266371
> 
> 
> > On Jul 18, 2017, at 4:41 PM, kurt greaves  wrote:
> > 
> > select a, writetime(b) from test.t
> 
> 

-
To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
For additional commands, e-mail: user-h...@cassandra.apache.org

Re: Solutions.Hamburg conference speaking opportunity

[Jeff Jirsa]

On 2017-07-19 02:05 (-0700), Myrle Krantz  wrote: 
> Hello Apache Cassandra Community,
> 
> Solutions.Hamburg is offering Apache conference speaking slots, and
> some time to advertise for the ASF.  We were wondering if anyone in
> the Cassandra community would like to give a technical talk on Apache
> Cassandra, between September 6-8 in Hamburg.
> 
> This is an opportunity to get extra exposure for Apache, for your
> project, and for yourself.  Anyone interested?
> 

Seems like a blast, but pretty short notice. dev@cassandra.a.o has a pretty 
wide audience, may be worth crossposting there. 


> 
> P.S. I've been using Cassandra in our rearchitecting of Apache
> Fineract, and I'm a huge fan.  Keep up the good work y'all!

Glad you're enjoying it!

-
To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
For additional commands, e-mail: user-h...@cassandra.apache.org

Re: Cassandra 2.2.6 Fails to Boot Up correctly - JNA Class

[Jeff Jirsa]

On 2017-07-19 10:41 (-0700), William Boutin  
wrote: 
> We are running apache-cassandra-2.2.6 for months with no JNA startup issues.
> Recently, we have updated some of our cassandra machines and we ran into a 
> Cassandra startup issue with JNA. See the stack trace 1 below.
> 
> Question 1: Our Cassandra package contains jna-4.0.0.jar in the 
> /usr/share/cassandra/lib/ directory. Does apache-cassandra-2.2.6 specifically 
> package A-C* with the jna-4.0.0.jar ?
> 

Yes, we explicitly bundle jna-4.0.0.jar for 2.2.6 

This is unchanged in 2.2 since 
https://github.com/apache/cassandra/commit/2ba394676dc673b6d66a07247dccd122b64b0578
 ( Jan 2014, when it was cassandra 2.1 beta).

Is the jar missing? Did another version of jna get installed? If a system 
package got installed, you may have multiple versions in the classpath. 

> I tried to circumvent the exception by yum installing  jna-3.2.4.jar for RHEL 
> 6.4 and adding it to the /usr/share/cassandra/lib/ directory. This got me 
> past the JNA mlockall failure with "INFO  16:56:47 JNA mlockall successful" 
> but when the MemtableFlushWriter requested memory allocation, I now get the 
> STACK TRACE 2 error. "nodetool status" still reports the node as incomplete.
> 

Installing 3.2.4 is probably not going to work (as hinted in my earlier 
paragraph); you almost certainly want 4.0 or newer, and you should probably 
want exactly one jna jar in the classpath at any given time.
 


- Jeff

-
To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
For additional commands, e-mail: user-h...@cassandra.apache.org

Re: Sync Spark Data with Cassandra Using Incremental Data Loading

[Justin Cameron]

The easiest way to do this is to create another Cassandra DC and point
Spark to it, since Spark can operate directly on data in Cassandra. No
impact on C* performance and no complex backup/restore process required,
just let Cassandra replicate the data for you.

If you need a scalable bulk export/import solution on your production data
that doesn't affect C* performance I would look at doing something like
this: https://www.youtube.com/watch?v=eY5oSZnwmJg . It's the best solution
I've seen to the problem.

On Wed, 19 Jul 2017 at 23:42 Fd Habash  wrote:

> I have a scenario where data has to be loaded into Spark nodes from two
> data stores: Oracle and Cassandra. We did the initial loading of data and
> found a way to do daily incremental loading from Oracle to Spark.
>
>
>
> I’m tying to figure our how to do this from C*. What tools are available
> in C* to do incremental backup/restore/load?
>
>
>
> Thanks
>
-- 


*Justin Cameron*Senior Software Engineer





This email has been sent on behalf of Instaclustr Pty. Limited (Australia)
and Instaclustr Inc (USA).

This email and any attachments may contain confidential and legally
privileged information.  If you are not the intended recipient, do not copy
or disclose its content, but please reply to this email immediately and
highlight the error to the sender and then immediately delete the message.

Re: Nodetool tablehistograms

[Chris Lohfink]

Its the number of sstables that may of been read from. This includes
sstables who had their bloom filters checked (which may hit disk). This
changes a bit in https://issues.apache.org/jira/browse/CASSANDRA-13120 to
be only the sstables that its actually reading from.


On Wed, Jul 19, 2017 at 11:04 AM, Abhinav Solan 
wrote:

> Hi Everyone,
>
> Here is the result of my tablehistograms command on one of our tables.
>
> Percentile  SSTables Write Latency  Read LatencyPartition Size
>Cell Count
>   (micros)  (micros)   (bytes)
> 50% 4.00 73.46545.79152321
>  8239
> 75%10.00 88.15   2346.80379022
> 20501
> 95%10.00152.32   4055.27   1358102
> 73457
> 98%10.00219.34   4866.32   1955666
> 88148
> 99%10.00315.85   5839.59   1955666
>105778
> Min 0.00 17.09 35.4373
> 3
> Max10.00  36157.19  52066.35   2816159
>152321
>
> What does SSTables column represent here?
> Does it mean how many SSTables the read is spanning to?
>
> Thanks,
> Abhinav
>

Nodetool tablehistograms

[Abhinav Solan]

Hi Everyone,

Here is the result of my tablehistograms command on one of our tables.

Percentile  SSTables Write Latency  Read LatencyPartition Size
   Cell Count
  (micros)  (micros)   (bytes)
50% 4.00 73.46545.79152321
 8239
75%10.00 88.15   2346.80379022
20501
95%10.00152.32   4055.27   1358102
73457
98%10.00219.34   4866.32   1955666
88148
99%10.00315.85   5839.59   1955666
   105778
Min 0.00 17.09 35.4373
3
Max10.00  36157.19  52066.35   2816159
   152321

What does SSTables column represent here?
Does it mean how many SSTables the read is spanning to?

Thanks,
Abhinav

Cassandra 2.2.6 Fails to Boot Up correctly - JNA Class

[William Boutin]

We are running apache-cassandra-2.2.6 for months with no JNA startup issues.
Recently, we have updated some of our cassandra machines and we ran into a 
Cassandra startup issue with JNA. See the stack trace 1 below.

Question 1: Our Cassandra package contains jna-4.0.0.jar in the 
/usr/share/cassandra/lib/ directory. Does apache-cassandra-2.2.6 specifically 
package A-C* with the jna-4.0.0.jar ?

I tried to circumvent the exception by yum installing  jna-3.2.4.jar for RHEL 
6.4 and adding it to the /usr/share/cassandra/lib/ directory. This got me past 
the JNA mlockall failure with "INFO  16:56:47 JNA mlockall successful" but when 
the MemtableFlushWriter requested memory allocation, I now get the STACK TRACE 
2 error. "nodetool status" still reports the node as incomplete.

Any Suggestions?

Thank you

STACK TRACE 1:
ERROR [MemtableFlushWriter:1] 2017-07-17 22:33:13,376 CassandraDaemon.java:185 
- Exception in thread Thread[MemtableFlushWriter:1,5,main]
java.lang.NoClassDefFoundError: Could not initialize class com.sun.jna.Native
at 
org.apache.cassandra.utils.memory.MemoryUtil.allocate(MemoryUtil.java:82) 
~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at org.apache.cassandra.io.util.Memory.(Memory.java:74) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at org.apache.cassandra.io.util.SafeMemory.(SafeMemory.java:32) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressionMetadata$Writer.(CompressionMetadata.java:304)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressionMetadata$Writer.open(CompressionMetadata.java:318)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressedSequentialWriter.(CompressedSequentialWriter.java:73)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.util.SequentialWriter.open(SequentialWriter.java:168) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.sstable.format.big.BigTableWriter.(BigTableWriter.java:75)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.sstable.format.big.BigFormat$WriterFactory.open(BigFormat.java:107)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.sstable.format.SSTableWriter.create(SSTableWriter.java:84)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.db.Memtable$FlushRunnable.createFlushWriter(Memtable.java:433)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:376)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.db.Memtable$FlushRunnable.runMayThrow(Memtable.java:361) 
~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28) 
~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
com.google.common.util.concurrent.MoreExecutors$SameThreadExecutorService.execute(MoreExecutors.java:297)
 ~[guava-16.0.jar:na]
at 
org.apache.cassandra.db.ColumnFamilyStore$Flush.run(ColumnFamilyStore.java:1146)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
~[na:1.7.0_141]
at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
~[na:1.7.0_141]
at java.lang.Thread.run(Thread.java:745) ~[na:1.7.0_141]

STACK TRACE 2:
ERROR 16:56:51 Exception in thread Thread[MemtableFlushWriter:1,5,main]
java.lang.NoSuchMethodError: com.sun.jna.Native.malloc(J)J
at 
org.apache.cassandra.utils.memory.MemoryUtil.allocate(MemoryUtil.java:82) 
~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at org.apache.cassandra.io.util.Memory.(Memory.java:74) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at org.apache.cassandra.io.util.SafeMemory.(SafeMemory.java:32) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressionMetadata$Writer.(CompressionMetadata.java:304)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressionMetadata$Writer.open(CompressionMetadata.java:318)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.compress.CompressedSequentialWriter.(CompressedSequentialWriter.java:73)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.util.SequentialWriter.open(SequentialWriter.java:168) 
~[apache-cassandra-clientutil-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.sstable.format.big.BigTableWriter.(BigTableWriter.java:75)
 ~[apache-cassandra-2.2.6-E002.jar:2.2.6-E002]
at 
org.apache.cassandra.io.sstable.format.big.BigFormat$WriterFactory.open(BigFormat.java:107)
 

Re: write time for nulls is not consistent

[Nitan Kainth]

Same output Kurt,

[cqlsh 5.0.1 | Cassandra 3.0.10.1443 | DSE 5.0.4 | CQL spec 3.4.0 | Native 
protocol v4]
Use HELP for help.
cqlsh> select a, writetime(b) from test.t;

 a | writetime(b)
---+--
 z | null
 a | null
 c | null
 e | null
 r | null
 d | 1500400745074499
 w | 1500400745074499
 v | 1500400745074499
 t | 1500400745074499
 x | 1500400626266371


> On Jul 18, 2017, at 4:41 PM, kurt greaves  wrote:
> 
> select a, writetime(b) from test.t

Sync Spark Data with Cassandra Using Incremental Data Loading

[Fd Habash]

I have a scenario where data has to be loaded into Spark nodes from two data 
stores: Oracle and Cassandra. We did the initial loading of data and found a 
way to do daily incremental loading from Oracle to Spark. 

I’m tying to figure our how to do this from C*. What tools are available in C* 
to do incremental backup/restore/load?

Thanks 

Solutions.Hamburg conference speaking opportunity

[Myrle Krantz]

Hello Apache Cassandra Community,

Solutions.Hamburg is offering Apache conference speaking slots, and
some time to advertise for the ASF.  We were wondering if anyone in
the Cassandra community would like to give a technical talk on Apache
Cassandra, between September 6-8 in Hamburg.

This is an opportunity to get extra exposure for Apache, for your
project, and for yourself.  Anyone interested?

Best Regards,
Myrle Krantz


FYI: This is the thread in d...@community.apache.org:
https://lists.apache.org/thread.html/c0efc33f8f4054f180a54ac97bcf04a30f2e510d63f510bb87e1983b@%3Cdev.community.apache.org%3E

P.S. I've been using Cassandra in our rearchitecting of Apache
Fineract, and I'm a huge fan.  Keep up the good work y'all!

-
To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
For additional commands, e-mail: user-h...@cassandra.apache.org