Nodetool tablehistograms
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
Re: Row cache not working
It's cassandra 3.0.7,
I had to set caching = {'keys': 'ALL', 'rows_per_partition': 'ALL'}, then
only it works don't know why.
If I set 'rows_per_partition':'1' then it does not work.
Also wanted to ask one thing, if I set row_cache_save_period: 60 then this
cache would be refreshed automatically or it would be lazy, whenever the
fetch call is made then only it caches it.
On Mon, Oct 3, 2016 at 1:31 PM Jeff Jirsa <jeff.ji...@crowdstrike.com>
wrote:
> Which version of Cassandra are you running (I can tell it’s newer than
> 2.1, but exact version would be useful)?
>
>
>
> *From: *Abhinav Solan <abhinav.so...@gmail.com>
> *Reply-To: *"user@cassandra.apache.org" <user@cassandra.apache.org>
> *Date: *Monday, October 3, 2016 at 11:35 AM
> *To: *"user@cassandra.apache.org" <user@cassandra.apache.org>
> *Subject: *Re: Row cache not working
>
>
>
> Hi, can anyone please help me with this
>
>
>
> Thanks,
>
> Abhinav
>
>
>
> On Fri, Sep 30, 2016 at 6:20 PM Abhinav Solan <abhinav.so...@gmail.com>
> wrote:
>
> Hi Everyone,
>
>
>
> My table looks like this -
>
> CREATE TABLE test.reads (
>
> svc_pt_id bigint,
>
> meas_type_id bigint,
>
> flags bigint,
>
> read_time timestamp,
>
> value double,
>
> PRIMARY KEY ((svc_pt_id, meas_type_id))
>
> ) WITH bloom_filter_fp_chance = 0.1
>
> AND caching = {'keys': 'ALL', 'rows_per_partition': '10'}
>
> AND comment = ''
>
> AND compaction = {'class':
> 'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'}
>
> AND compression = {'chunk_length_in_kb': '64', 'class':
> 'org.apache.cassandra.io.compress.LZ4Compressor'}
>
> AND crc_check_chance = 1.0
>
> AND dclocal_read_repair_chance = 0.1
>
> AND default_time_to_live = 0
>
> AND gc_grace_seconds = 864000
>
> AND max_index_interval = 2048
>
> AND memtable_flush_period_in_ms = 0
>
> AND min_index_interval = 128
>
> AND read_repair_chance = 0.0
>
> AND speculative_retry = '99PERCENTILE';
>
>
>
> Have set up the C* nodes with
>
> row_cache_size_in_mb: 1024
>
> row_cache_save_period: 14400
>
>
>
> and I am making this query
>
> select svc_pt_id, meas_type_id, read_time, value FROM
> cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
> 146;
>
>
>
> with tracing on every time it says Row cache miss
>
>
>
> activity
>
>| timestamp | source | source_elapsed
>
>
> ---++-+
>
>
>
> Execute CQL3 query | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
> 0
>
> Parsing select svc_pt_id, meas_type_id, read_time, value FROM
> cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
> 146; [SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
>111
>
>
>Preparing statement
> [SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
>209
>
>
> reading data from /192.168.170.186
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__192.168.170.186=DQMGaQ=08AGY6txKsvMOP6lYkHQpPMRA1U6kqhAwGa8-0QCg3M=yfYEBHVkX6l0zImlOIBID0gmhluYPD5Jje-3CtaT3ow=TzZ71ThTYrI2Cs7eYc2nhu4gOJpHM6B89KY97yj0Pp4=Rsg4cca5QVAWlI6cS1M673hWQ66Jxg2B5zK-HoJ6ZlQ=>
> [SharedPool-Worker-1] | 2016-09-30 18:15:00.446001 | 192.168.199.75 |
>370
>
>
>Sending READ message to /192.168.170.186
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__192.168.170.186=DQMGaQ=08AGY6txKsvMOP6lYkHQpPMRA1U6kqhAwGa8-0QCg3M=yfYEBHVkX6l0zImlOIBID0gmhluYPD5Jje-3CtaT3ow=TzZ71ThTYrI2Cs7eYc2nhu4gOJpHM6B89KY97yj0Pp4=Rsg4cca5QVAWlI6cS1M673hWQ66Jxg2B5zK-HoJ6ZlQ=>
> [MessagingService-Outgoing-/192.168.170.186
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__192.168.170.186=DQMGaQ=08AGY6txKsvMOP6lYkHQpPMRA1U6kqhAwGa8-0QCg3M=yfYEBHVkX6l0zImlOIBID0gmhluYPD5Jje-3CtaT3ow=TzZ71ThTYrI2Cs7eYc2nhu4gOJpHM6B89KY97yj0Pp4=Rsg4cca5QVAWlI6cS1M673hWQ66Jxg2B5zK-HoJ6ZlQ=>]
> | 2016-09-30 18:15:00.446001 | 192.168.199.75 |450
>
>
> REQUEST_RESPONSE message received from /192.168.170.186
> <https://urldefense.proofpoint.com/v2/url?u=http-3A__192.168.170.186=DQMGaQ=08AGY6txKsvMOP6lYkHQpPMRA1U6kqhAwGa8-0QCg3M=yfYEBHVkX6l0zImlOIBID0gmhluYPD5Jje-3CtaT3ow=TzZ71ThTYrI2Cs7eYc2nhu4gOJpHM6B89KY97yj0Pp4=Rsg4cca5QVAWlI6cS
Re: Row cache not working
Hi, can anyone please help me with this
Thanks,
Abhinav
On Fri, Sep 30, 2016 at 6:20 PM Abhinav Solan <abhinav.so...@gmail.com>
wrote:
> Hi Everyone,
>
> My table looks like this -
> CREATE TABLE test.reads (
> svc_pt_id bigint,
> meas_type_id bigint,
> flags bigint,
> read_time timestamp,
> value double,
> PRIMARY KEY ((svc_pt_id, meas_type_id))
> ) WITH bloom_filter_fp_chance = 0.1
> AND caching = {'keys': 'ALL', 'rows_per_partition': '10'}
> AND comment = ''
> AND compaction = {'class':
> 'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'}
> AND compression = {'chunk_length_in_kb': '64', 'class':
> 'org.apache.cassandra.io.compress.LZ4Compressor'}
> AND crc_check_chance = 1.0
> AND dclocal_read_repair_chance = 0.1
> AND default_time_to_live = 0
> AND gc_grace_seconds = 864000
> AND max_index_interval = 2048
> AND memtable_flush_period_in_ms = 0
> AND min_index_interval = 128
> AND read_repair_chance = 0.0
> AND speculative_retry = '99PERCENTILE';
>
> Have set up the C* nodes with
> row_cache_size_in_mb: 1024
> row_cache_save_period: 14400
>
> and I am making this query
> select svc_pt_id, meas_type_id, read_time, value FROM
> cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
> 146;
>
> with tracing on every time it says Row cache miss
>
> activity
>
>| timestamp | source | source_elapsed
>
> ---++-+
>
>
> Execute CQL3 query | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
> 0
> Parsing select svc_pt_id, meas_type_id, read_time, value FROM
> cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
> 146; [SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
>111
>
>Preparing statement
> [SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
>209
>
> reading data from /192.168.170.186
> [SharedPool-Worker-1] | 2016-09-30 18:15:00.446001 | 192.168.199.75 |
>370
>
>Sending READ message to /192.168.170.186 [MessagingService-Outgoing-/
> 192.168.170.186] | 2016-09-30 18:15:00.446001 | 192.168.199.75 |
>450
>
> REQUEST_RESPONSE message received from /192.168.170.186
> [MessagingService-Incoming-/192.168.170.186] | 2016-09-30 18:15:00.448000
> | 192.168.199.75 | 2469
>
> Processing response from /192.168.170.186
> [SharedPool-Worker-8] | 2016-09-30 18:15:00.448000 | 192.168.199.75 |
> 2609
>
> READ message received from /192.168.199.75 [MessagingService-Incoming-/
> 192.168.199.75] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
> 75
>
> Row cache miss
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
>218
> Fetching data but not
> populating cache as query does not query from the start of the partition
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
>246
>
> Executing single-partition query on cts_svc_pt_latest_int_read
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
>259
>
> Acquiring sstable references
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>281
>
> Merging memtable contents
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>295
>
>Merging data from sstable 8
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>326
>
>Key cache hit for sstable 8
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>351
>
>Merging data from sstable 7
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>439
>
>Key cache hit for sstable 7
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>468
>
> Read 1 live and 0 tombstone cells
> [SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
>615
>
>
Row cache not working
Hi Everyone,
My table looks like this -
CREATE TABLE test.reads (
svc_pt_id bigint,
meas_type_id bigint,
flags bigint,
read_time timestamp,
value double,
PRIMARY KEY ((svc_pt_id, meas_type_id))
) WITH bloom_filter_fp_chance = 0.1
AND caching = {'keys': 'ALL', 'rows_per_partition': '10'}
AND comment = ''
AND compaction = {'class':
'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'}
AND compression = {'chunk_length_in_kb': '64', 'class':
'org.apache.cassandra.io.compress.LZ4Compressor'}
AND crc_check_chance = 1.0
AND dclocal_read_repair_chance = 0.1
AND default_time_to_live = 0
AND gc_grace_seconds = 864000
AND max_index_interval = 2048
AND memtable_flush_period_in_ms = 0
AND min_index_interval = 128
AND read_repair_chance = 0.0
AND speculative_retry = '99PERCENTILE';
Have set up the C* nodes with
row_cache_size_in_mb: 1024
row_cache_save_period: 14400
and I am making this query
select svc_pt_id, meas_type_id, read_time, value FROM
cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
146;
with tracing on every time it says Row cache miss
activity
| timestamp | source | source_elapsed
---++-+
Execute
CQL3 query | 2016-09-30 18:15:00.446000 | 192.168.199.75 | 0
Parsing select svc_pt_id, meas_type_id, read_time, value FROM
cts_svc_pt_latest_int_read where svc_pt_id = -9941235 and meas_type_id =
146; [SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
111
Preparing statement
[SharedPool-Worker-1] | 2016-09-30 18:15:00.446000 | 192.168.199.75 |
209
reading data from /192.168.170.186
[SharedPool-Worker-1] | 2016-09-30 18:15:00.446001 | 192.168.199.75 |
370
Sending READ message to /192.168.170.186 [MessagingService-Outgoing-/
192.168.170.186] | 2016-09-30 18:15:00.446001 | 192.168.199.75 |
450
REQUEST_RESPONSE message received from /192.168.170.186
[MessagingService-Incoming-/192.168.170.186] | 2016-09-30 18:15:00.448000 |
192.168.199.75 | 2469
Processing response from /192.168.170.186
[SharedPool-Worker-8] | 2016-09-30 18:15:00.448000 | 192.168.199.75 |
2609
READ message received from /192.168.199.75 [MessagingService-Incoming-/
192.168.199.75] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
75
Row cache miss
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
218
Fetching data but not
populating cache as query does not query from the start of the partition
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
246
Executing single-partition query on cts_svc_pt_latest_int_read
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449000 | 192.168.170.186 |
259
Acquiring sstable references
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
281
Merging memtable contents
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
295
Merging data from sstable 8
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
326
Key cache hit for sstable 8
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
351
Merging data from sstable 7
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
439
Key cache hit for sstable 7
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
468
Read 1 live and 0 tombstone cells
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449001 | 192.168.170.186 |
615
Enqueuing response to /192.168.199.75
[SharedPool-Worker-2] | 2016-09-30 18:15:00.449002 | 192.168.170.186 |
766
Sending
REQUEST_RESPONSE message to /192.168.199.75 [MessagingService-Outgoing-/
192.168.199.75] | 2016-09-30 18:15:00.449002 | 192.168.170.186 |
897
Request complete | 2016-09-30 18:15:00.44 | 192.168.199.75 |
2888
Can please anyone tell me what I am doing wrong?
Thanks,
Abhinav
Re: NoHostAvailableException coming up on our server
Thanks a lot for suggestion Romain, I have done the setup to see the driver logs, but haven't seen that error again. Also thanks for the MaxRequestPerConnection tip, I will change it to 32K. Regards, Abhinav On Wed, Jul 13, 2016 at 1:02 PM Romain Hardouin <romainh...@yahoo.fr> wrote: > Put the driver logs in debug mode to see what's happen. > Btw I am surprised by the few requests by connections in your setup: > > .setConnectionsPerHost(HostDistance.LOCAL, 20, 20) > .setMaxRequestsPerConnection(HostDistance.LOCAL, 128) > > It looks like a protocol v2 settings (Cassandra 2.0) because it was > limited to 128 requests per connection. You're using C* 3.3 so the protocol > v4. > You can go up to 32K since protocol v3. As a first step I would try to > open only 2 connections with 16K in MaxRequestsPerConnection. Then try to > fine tune. > > Best, > > Romain > > > Le Mardi 12 juillet 2016 23h57, Abhinav Solan <abhinav.so...@gmail.com> a > écrit : > > > I am using 3.0.0 version over apache-cassandra-3.3 > > On Tue, Jul 12, 2016 at 2:37 PM Riccardo Ferrari <ferra...@gmail.com> > wrote: > > What driver version are you using? > > You can look at the LoggingRetryPolicy to have more meaningful messages in > your logs. > > best, > > On Tue, Jul 12, 2016 at 9:02 PM, Abhinav Solan <abhinav.so...@gmail.com> > wrote: > > Thanks, Johnny > Actually, they were running .. it went through a series of read and writes > .. and recovered after the error. > Is there any settings I can specify in preparing the Session at java > client driver level, here are my current settings - > > PoolingOptions poolingOptions = new PoolingOptions() > .setConnectionsPerHost(HostDistance.LOCAL, 20, 20) > .setMaxRequestsPerConnection(HostDistance.LOCAL, 128) > .setNewConnectionThreshold(HostDistance.LOCAL, 100); > > Cluster.Builder builder = Cluster.builder() > .addContactPoints(cp) > .withPoolingOptions(poolingOptions) > .withProtocolVersion(ProtocolVersion.NEWEST_SUPPORTED) > .withPort(port); > > > > On Tue, Jul 12, 2016 at 11:47 AM Johnny Miller <johnny.p.mil...@gmail.com> > wrote: > > Abhinav - your getting that as the driver isn’t finding any hosts up for > your query. You probably need to check if all the nodes in your cluster are > running. > > See: > http://docs.datastax.com/en/drivers/java/3.0/com/datastax/driver/core/exceptions/NoHostAvailableException.html > > > Johnny > > On 12 Jul 2016, at 18:46, Abhinav Solan <abhinav.so...@gmail.com> wrote: > > Hi Everyone, > > I am getting this error on our server, it comes and goes seems the > connection drops a comes back after a while - > > Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All > host(s) tried for query failed (tried: :9042 > (com.datastax.driver.core.exceptions.ConnectionException: [] > Pool is CLOSING)) > at > com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:218) > at > com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:43) > at > com.datastax.driver.core.RequestHandler$SpeculativeExecution.sendRequest(RequestHandler.java:284) > at > com.datastax.driver.core.RequestHandler.startNewExecution(RequestHandler.java:115) > at > com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:91) > at > com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:129) > > Can anyone suggest me what can be done to handle this error ? > > > Thanks, > > Abhinav > > > > > >
Re: NoHostAvailableException coming up on our server
I am using 3.0.0 version over apache-cassandra-3.3 On Tue, Jul 12, 2016 at 2:37 PM Riccardo Ferrari <ferra...@gmail.com> wrote: > What driver version are you using? > > You can look at the LoggingRetryPolicy to have more meaningful messages in > your logs. > > best, > > On Tue, Jul 12, 2016 at 9:02 PM, Abhinav Solan <abhinav.so...@gmail.com> > wrote: > >> Thanks, Johnny >> Actually, they were running .. it went through a series of read and >> writes .. and recovered after the error. >> Is there any settings I can specify in preparing the Session at java >> client driver level, here are my current settings - >> >> PoolingOptions poolingOptions = new PoolingOptions() >> .setConnectionsPerHost(HostDistance.LOCAL, 20, 20) >> .setMaxRequestsPerConnection(HostDistance.LOCAL, 128) >> .setNewConnectionThreshold(HostDistance.LOCAL, 100); >> >> Cluster.Builder builder = Cluster.builder() >> .addContactPoints(cp) >> .withPoolingOptions(poolingOptions) >> .withProtocolVersion(ProtocolVersion.NEWEST_SUPPORTED) >> .withPort(port); >> >> >> >> On Tue, Jul 12, 2016 at 11:47 AM Johnny Miller <johnny.p.mil...@gmail.com> >> wrote: >> >>> Abhinav - your getting that as the driver isn’t finding any hosts up for >>> your query. You probably need to check if all the nodes in your cluster are >>> running. >>> >>> See: >>> http://docs.datastax.com/en/drivers/java/3.0/com/datastax/driver/core/exceptions/NoHostAvailableException.html >>> >>> >>> Johnny >>> >>> On 12 Jul 2016, at 18:46, Abhinav Solan <abhinav.so...@gmail.com> wrote: >>> >>> Hi Everyone, >>> >>> I am getting this error on our server, it comes and goes seems the >>> connection drops a comes back after a while - >>> >>> Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: >>> All host(s) tried for query failed (tried: :9042 >>> (com.datastax.driver.core.exceptions.ConnectionException: >>> [] Pool is CLOSING)) >>> at >>> com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:218) >>> at >>> com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:43) >>> at >>> com.datastax.driver.core.RequestHandler$SpeculativeExecution.sendRequest(RequestHandler.java:284) >>> at >>> com.datastax.driver.core.RequestHandler.startNewExecution(RequestHandler.java:115) >>> at >>> com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:91) >>> at >>> com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:129) >>> >>> Can anyone suggest me what can be done to handle this error ? >>> >>> >>> Thanks, >>> >>> Abhinav >>> >>> >>> >
Re: NoHostAvailableException coming up on our server
Thanks, Johnny Actually, they were running .. it went through a series of read and writes .. and recovered after the error. Is there any settings I can specify in preparing the Session at java client driver level, here are my current settings - PoolingOptions poolingOptions = new PoolingOptions() .setConnectionsPerHost(HostDistance.LOCAL, 20, 20) .setMaxRequestsPerConnection(HostDistance.LOCAL, 128) .setNewConnectionThreshold(HostDistance.LOCAL, 100); Cluster.Builder builder = Cluster.builder() .addContactPoints(cp) .withPoolingOptions(poolingOptions) .withProtocolVersion(ProtocolVersion.NEWEST_SUPPORTED) .withPort(port); On Tue, Jul 12, 2016 at 11:47 AM Johnny Miller <johnny.p.mil...@gmail.com> wrote: > Abhinav - your getting that as the driver isn’t finding any hosts up for > your query. You probably need to check if all the nodes in your cluster are > running. > > See: > http://docs.datastax.com/en/drivers/java/3.0/com/datastax/driver/core/exceptions/NoHostAvailableException.html > > > Johnny > > On 12 Jul 2016, at 18:46, Abhinav Solan <abhinav.so...@gmail.com> wrote: > > Hi Everyone, > > I am getting this error on our server, it comes and goes seems the > connection drops a comes back after a while - > > Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All > host(s) tried for query failed (tried: :9042 > (com.datastax.driver.core.exceptions.ConnectionException: [] > Pool is CLOSING)) > at > com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:218) > at > com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:43) > at > com.datastax.driver.core.RequestHandler$SpeculativeExecution.sendRequest(RequestHandler.java:284) > at > com.datastax.driver.core.RequestHandler.startNewExecution(RequestHandler.java:115) > at > com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:91) > at > com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:129) > > Can anyone suggest me what can be done to handle this error ? > > > Thanks, > > Abhinav > > >
NoHostAvailableException coming up on our server
Hi Everyone, I am getting this error on our server, it comes and goes seems the connection drops a comes back after a while - Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: :9042 (com.datastax.driver.core.exceptions.ConnectionException: [] Pool is CLOSING)) at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:218) at com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:43) at com.datastax.driver.core.RequestHandler$SpeculativeExecution.sendRequest(RequestHandler.java:284) at com.datastax.driver.core.RequestHandler.startNewExecution(RequestHandler.java:115) at com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:91) at com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:129) Can anyone suggest me what can be done to handle this error ? Thanks, Abhinav
Blob or columns
Hi Everyone, We have a unique situation at my workplace while storing data. We are using Cassandra as a write through cache where we keep real time data in Cassandra for around 10 - 20 days and rest we archive it to another data store as archived data. The current data which we are going to store has around 20 columns, of which 3 would be used in primary key and 2 more would be read by systems which would query while working on Cassandra, rest of the columns are of no use, only use of these columns are when these would be required re-construct the data to be archived in our archive store which would be accessed by our legacy applications. The question here is - Should we store these inconsequential data as blob or JSON in one column or create separate columns for them, which one should be the preferred way here ? We are currently using Cassandra 3.x version. Thanks, Abhinav
