Hi All.
I have been doing extensive testing, and replication works fine, even if
any permuatation of CAS11, CAS12, CAS21, CAS22 are downed and brought up.
Syncing always takes place (obviously, as long as continuous-downtime-value
does not exceed *max_hint_window_in_ms*).
However, things behave weird when I try connecting via DataStax Java-Driver.
I always add the nodes to the cluster in the order ::
CAS11, CAS12, CAS21, CAS22
during "cluster.connect" method.
Now, following happens ::
a)
If CAS11 goes down, data is persisted fine (presumably first in CAS12, and
later replicated to CAS21 and CAS22).
b)
If CAS11 and CAS12 go down, data is NOT persisted.
Instead the following exceptions are observed in the Java-Driver ::
##################################################################################
Exception in thread "main"
com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s)
tried for query failed (no host was tried)
at
com.datastax.driver.core.exceptions.NoHostAvailableException.copy(NoHostAvailableException.java:65)
at
com.datastax.driver.core.DefaultResultSetFuture.extractCauseFromExecutionException(DefaultResultSetFuture.java:258)
at com.datastax.driver.core.Cluster.connect(Cluster.java:267)
at com.example.cassandra.SimpleClient.connect(SimpleClient.java:43)
at
com.example.cassandra.SimpleClientTest.setUp(SimpleClientTest.java:50)
at com.example.cassandra.SimpleClientTest.main(SimpleClientTest.java:86)
Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException:
All host(s) tried for query failed (no host was tried)
at
com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:103)
at
com.datastax.driver.core.SessionManager.execute(SessionManager.java:446)
at
com.datastax.driver.core.SessionManager.executeQuery(SessionManager.java:482)
at
com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:88)
at
com.datastax.driver.core.AbstractSession.executeAsync(AbstractSession.java:60)
at com.datastax.driver.core.Cluster.connect(Cluster.java:260)
... 3 more
###################################################################################
I have already tried ::
1)
Increasing driver-read-timeout from 12 seconds to 30 seconds.
2)
Increasing driver-connect-timeout from 5 seconds to 30 seconds.
3)
I have also confirmed that each of the 4 nodes are telnet-able over ports
9042 and 9160 each.
Definitely seems to be some driver-issue, since
data-persistence/replication works perfect (with any permutation) if
data-persistence is done via "cqlsh".
Kindly provide some pointers.
Ultimately, it is the Java-driver that will be used in production, so it is
imperative that data-persistence/replication happens for any downing of any
permutation of node(s).
Thanks and Regards,
Ajay
