Frequently Asked Questions
This section contains answers to common questions and recommendations for common issues.
Issues With Clusters
My cluster failed to start
If your cluster failed to start during provisioning, try to provision one more cluster with the same settings. Sometimes cloud-related issues happen during provisioning, and the cluster fails to start and connect to GridGain Nebula. These issues are investigated by the support team.
You will not be billed for the cluster that did not start.
My cluster is disconnected
A disconnected cluster is still running, just not connected to GridGain Nebula. Click the ⋮ and select Connect to reconnect to the cluster.
My cluster shows the Limited Cluster banner
GridGain Nebula monitors Tracing and Compute activity of your cluster and imposes activity limitations:
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Soft limit: When the number of Tracing or Compute messages in the corresponding queue exceeds the "soft" threshold (by default, 200), GridGain Nebula attempts to automatically reduce message submission rate for your cluster.
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Hard limit: When the number of Tracing or Compute messages in the corresponding queue exceeds the "hard" threshold (by default, 1,000), your cluster enters the "limited" state wherein no new Tracing or Compute messages are added to the queues. In all other respects, your cluster remains active and functional. By default, the limited state (a.k.a., "ban") lasts 3 minutes. After that, GridGain Nebula checks the status of the Tracing and Compute queues. If it finds that the number of messages diminished below the threshold, the cluster resumes its normal operation. If the number of messages is still above the threshold, the cluster remains in the limited state for another 3 minutes.
To preclude your cluster from entering the limited state, reduce the Tracing percentage for one or more scopes. If this does not help, contact our support.
GridGain Nebula lost connection to my attached cluster after restart
The most common cause for connection loss is a cluster ID change. This can happen during the restart of an in-memory cluster, or if persistent data storage was lost for a persistent cluster.
If this happened, you can reattach the cluster using the Cloud Connector and continue monitoring it. However, previously collected data and configuration settings will be lost.
To avoid losing cluster information, configure a persistent cluster ID on your GridGain cluster before attaching it to GridGain Nebula.
Preserving Cluster ID for Attached Clusters
When starting your cluster, you need to set a persistent cluster ID and secret:
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Start your cluster and activate it.
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Run the following commands in this order:
control.sh --property set --name control-center-agent-cluster-secret --val 88f5ea3c-9e50-11ec-b909-0242ac120002 --yes control.sh --change-id 11111111-1111-1111-1111-111111111111 --yes control.sh --change-tag prod_cluster --yes
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Connect your cluster to GridGain Nebula using the Cloud Connector.
If you lose persistence, run all commands again before reconnecting to GridGain Nebula.
For persistent clusters, consider setting these properties during cluster startup to avoid connection loss. For in-memory clusters, consider adding a small persistent data region to store system information while keeping your data in-memory.
Connection Issues
I cannot connect to a newly created cluster
Sometimes DNS propagation may take time and, until it is complete, your cluster would not be available. If you see unknown host error when you try to connect, try running the nslookup your_cluster_address command. If the command fails to find the cluster, wait for a bit and try again.
I am getting SSL error during connection
Most likely you are using an older client version. For example, here is an error you can get in Java:
class org.apache.ignite.IgniteException: Failed to initialize SSL context (parameter cannot be null): keyStoreFilePath
at org.apache.ignite.ssl.SslContextFactory.create(SslContextFactory.java:559)
at org.apache.ignite.ssl.SslContextFactory.create(SslContextFactory.java:58)
at org.apache.ignite.spi.communication.tcp.internal.GridNioServerWrapper.resetNioServer(GridNioServerWrapper.java:853)You can see the required client version in connection templates.
My application cannot connect to the cluster
Most likely, you are using an incorrect client version. Please check that the client version is the same as the GridGain version run by Nebula cluster, and, if that does not help, contact us at support.cloud@gridgain.com.
How can I switch to Nebula from GridGain?
Currently, migration process is manual. Contact our support team for detailed instructions and assistance.
How do I contact support?
To contact support from the UI, use the Contact Us button in top-right of the screen. You can also send an e-mail to support.cloud@gridgain.com. Our team is constantly monitoring feedback.
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