Is there a way to restart Cassandra without restarting Spark worker in Datastax Enterprise (DSE)?
According to user Phact in the comment:
Currently this is not possible [...]
Related
I am running ignite on the k8s cluster with 5 pods and set backups = 1 https://apacheignite.readme.io/docs/primary-and-backup-copies. Is there any way to do a rolling restart without losing data and how to check if the data is synced to other instances before restarting one after another
Thank you
You can monitor cache rebalancing process by using jmx
https://ignite.apache.org/docs/latest/monitoring-metrics/metrics#monitoring-rebalancing
I was wondering why do we need Redis server for running CKAN.
If needed, why? And How do I configure it with CKAN?
p.s
I am running my ckan instance in RHEL7.
Update: Redis has been a requirement since CKAN 2.7, when a new system for asynchronous background jobs was introduced which relies on Redis. You can configure the Redis connection using the ckan.redis.url option.
Redis is not required for the current version of CKAN (2.6.2 at the time of this writing), it's not even mentioned in the CKAN 2.6.2 documentation.
However, the upcoming 2.7 release will require Redis for its new system of asynchronous background jobs. Redis will be configured using the new ckan.redis.url option.
We have an existing Hadoop cluster that is not managed by Ambari. Is it possible to install Apache Ambari on top of an existing Hadoop cluster?
No, Ambari must provision the cluster it's monitoring.
Ambari is designed around a Stack concept where each stack consists of several services. A stack definition is what allows Ambari to install, manage and monitor the services in the cluster.
I have Redis server running on CentOS as a service. I can stop the server using service redis stop or redis-cli SHUTDOWN.
What is the difference between the two options and which one I should be using in Production environment?
You should check your init script since it may precisely perform a shutdown on stop and not a killproc, e.g:
ExecStop=/usr/bin/redis-cli shutdown
(from Fedora package: redis-server.service)
Using shutdown is the recommended way to stop Redis if persistence matters as stated by the documentation:
If persistence is enabled this commands makes sure that Redis is switched off without the lost of any data.
Main OS is windows 7 64bit. Using VM player to create two vm CentOS 5.6 system. The net connection is bridge. I installed Hbase on both of the CentOS system， one is master, the other is slave. When I enter the shell, and run status 'details'.
The error from master is
zookeeper.ZKConfig: no valid quorum servers found in zoo.cfg ERROR:
org.apache.hadoop.hbase.ZooKeeperConnectionException: An error is
preventing HBase from connecting to ZooKeeper
And the error from slave is
ERROR: org.apache.hadoop.hbase.ZooKeeperConnectionException: HBase is
able to connect to ZooKeeper but the connection closes immediately.
This could be a sign that the server has too many connections (30 is
the default). Consider inspecting your ZK server logs for that error
and then make sure you are reusing HBaseConfiguration as often as you
can. See HTable's javadoc for more information.
Please give me some suggestion.
Thanks a lot
Check if this is within your .bashrc, if not, add them and restart all hbase services (do not forget to manually run them as well), that did it for me with a pseudo-distributed installation. My problem (and maybe yours as well) was that Hbase wasn't detecting it's configuration.
export HADOOP_CONF_DIR=/etc/hadoop/conf
export HBASE_CONF_DIR=/etc/hbase/conf
I see this very often on my machine. I don't have a failsafe cure, but end up running stop-all.sh, and deleting every place that hadoop and dfs (its a dfs failure) store their temp files. It seems to happen after my computer goes to sleep while dfs is running.
I am going to experiment with single-user mode to avoid this. I dont need distribution while developing.