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https://issues.apache.org/jira/browse/MESOS-8058?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Alexander Rukletsov updated MESOS-8058:
---
Description:
In {{2af9a5b07dc80151154264e974d03f56a1c25838}} we introduce the use of
{{UpdateSlaveMessage}} for the agent to inform the master about its current
total resources. Currently we trigger this message only on agent registration
and reregistration.
This can race with operations applied in the master and communicated via
{{CheckpointResourcesMessage}}.
Example:
1. Agent ({{cpus:4(\*)}} registers.
2. Master is triggered to apply an operation to the agent's resources, e.g., a
reservation: {{cpus:4(\*) -> cpus:4(A)}}. The master applies the operation to
its current view of the agent's resources and sends the agent a
{{CheckpointResourcesMessage}} so the agent can persist the result.
3. The agent sends the master an {{UpdateSlaveMessage}}, e.g., {{cpus:4(\*)}}
since it hasn't received the {{CheckpointResourcesMessage}} yet.
4. The master processes the {{UpdateSlaveMessage}} and updates its view of the
agent's resources to be {{cpus:4(\*)}}.
5. The agent processes the {{CheckpointResourcesMessage}} and updates its view
of its resources to be {{cpus:4(A)}}.
6. The agent and the master have an inconsistent view of the agent's resources.
was:
In {{2af9a5b07dc80151154264e974d03f56a1c25838}} we introduce the use of
{{UpdateSlaveMessage}} for the agent to inform the master about its current
total resources. Currently we trigger this message only on agent registration
and reregistration.
This can race with operations applied in the master and communicated via
{{CheckpointResourcesMessage}}.
Example:
1. Agent ({{cpus:4(\*)}} registers.
2. Master is triggered to apply an operation to the agent's resources, e.g., a
reservation: {{cpus:4(\*) -> cpus:4(A)}}. The master applies the operation to
its current view of the agent's resources and sends the agent a
{{CheckpointResourcesMessage}} so the agent can persist the result.
3. The agent send the master an {{UpdateSlaveMessage}}, e.g., {{cpus:4(\*)}}
since it hasn't received the {{CheckpointResourcesMessage}} yet.
4. The master processes the {{UpdateSlaveMessage}} and updates its view of the
agent's resources to be {{cpus:4(\*)}}.
5. The agent processes the {{CheckpointResourcesMessage}} and updates its view
of its resources to be {{cpus:4(A)}}.
6. The agent and the master have an inconsistent view of the agent's resources.
> Agent and master can race when updating agent state
> ---
>
> Key: MESOS-8058
> URL: https://issues.apache.org/jira/browse/MESOS-8058
> Project: Mesos
> Issue Type: Bug
> Components: agent
>Affects Versions: 1.5.0
>Reporter: Benjamin Bannier
>Assignee: Benjamin Bannier
>Priority: Critical
> Labels: mesosphere
>
> In {{2af9a5b07dc80151154264e974d03f56a1c25838}} we introduce the use of
> {{UpdateSlaveMessage}} for the agent to inform the master about its current
> total resources. Currently we trigger this message only on agent registration
> and reregistration.
> This can race with operations applied in the master and communicated via
> {{CheckpointResourcesMessage}}.
> Example:
> 1. Agent ({{cpus:4(\*)}} registers.
> 2. Master is triggered to apply an operation to the agent's resources, e.g.,
> a reservation: {{cpus:4(\*) -> cpus:4(A)}}. The master applies the operation
> to its current view of the agent's resources and sends the agent a
> {{CheckpointResourcesMessage}} so the agent can persist the result.
> 3. The agent sends the master an {{UpdateSlaveMessage}}, e.g., {{cpus:4(\*)}}
> since it hasn't received the {{CheckpointResourcesMessage}} yet.
> 4. The master processes the {{UpdateSlaveMessage}} and updates its view of
> the agent's resources to be {{cpus:4(\*)}}.
> 5. The agent processes the {{CheckpointResourcesMessage}} and updates its
> view of its resources to be {{cpus:4(A)}}.
> 6. The agent and the master have an inconsistent view of the agent's
> resources.
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