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https://issues.apache.org/jira/browse/IGNITE-18171?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17634803#comment-17634803
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Andrey Mashenkov edited comment on IGNITE-18171 at 11/16/22 1:49 PM:
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As node may participate is several groups, let's consider next possible roles
and their combinations.
Node roles:
* *CMG* (Cluster Management Group) is a subset of cluster nodes hosting a Raft
group. CMG leader is responsible for orchestrating the node join process.
* *MSG* (Meta Storage Group) is a subset of cluster nodes hosting a Raft group
responsible for storing a master copy of cluster metadata.
* *DNG* (Data Node Group) ** is a subset of cluster nodes hosting a Raft group
responsible for storing a master copy of user tables.
Node types:
A = []
B = [CMG]
C = [MSG]
D = [DNG]
E = [CMG, MSG]
F = [CMG, DNG]
G = [MSG, DNG]
H = [CMG, MSG, DNG]
was (Author: amashenkov):
As node may participate is several groups, let's consider next possible roles
and their combinations.
Node roles:
* *CMG* *is a subset of cluster nodes hosting a Raft group.* * *CMG* leader is
responsible for orchestrating the node join process.
* *MSG* is a subset of cluster nodes hosting a Raft group responsible for
storing a master copy of cluster metadata.
* *DNG* is a subset of cluster nodes hosting a Raft group responsible for
storing a master copy of user tables.
Node types:
A = []
B = [CMG]
C = [MSG]
D = [DNG]
E = [CMG, MSG]
F = [CMG, DNG]
G = [MSG, DNG]
H = [CMG, MSG, DNG]
> Descibe nodes start/stop scenarios
> ----------------------------------
>
> Key: IGNITE-18171
> URL: https://issues.apache.org/jira/browse/IGNITE-18171
> Project: Ignite
> Issue Type: Improvement
> Components: sql
> Reporter: Andrey Mashenkov
> Assignee: Andrey Mashenkov
> Priority: Major
> Labels: ignite-3
>
> h2. Definitions.
> We can distinguish next cluster node groups, see below. Each node may be part
> of one or more groups.
> 1. Cluster Management Group (CMG), that control new nodes join process.
> 2. MetaStorage group (MSG), that hosts meta storage.
> 3. Data node group (DNG), that just hosts tables partitions.
> The components (CMG, meta storage, tables components) are depends on each
> other, but may resides on different (even disjoint) node subsets. So, some
> components may become temporary unavailable, and dependant components must be
> aware of such issues and handle them (wait, retry, throw exception or
> whatever) in expected way, which has to be documented also.
> [See IEP for
> details|https://cwiki.apache.org/confluence/display/IGNITE/IEP-77%3A+Node+Join+Protocol+and+Initialization+for+Ignite+3]
> h2. Motivation.
> As of now, the correct way to start the grid (after it was stopped) is: start
> CMG nodes, then Meta Storage nodes, then Data nodes. And in backward order
> for correct stop. Other scenarios are not tested and may lead to unexpected
> behaviour.
> Let's describe all possible scenarios, expected behaviour for each of them
> and extend test coverage.
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