HDDS-11233. Ozone Storage Policy Support. #6989
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cc @sodonnel |
| | Tier | StorageType of Pipeline | One Replication | ||
| Container Replicas Storage Type | Three replication | ||
| Container Replicas Storage Type | EC | ||
| Container Replicas Storage Type | | ||
| | --- | --- | --- | --- | --- | | ||
| | SSD | SSD | SSD | 3 SSD | n SSD | | ||
| | DISK | DISK | DISK | 3 DISK | n DISK | | ||
| | ARCHIVE | ARCHIVE | ARCHIVE | 3 ARCHIVE | n ARCHIVE | |
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Nit: The table does not seem to be rendered properly.
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| | Storage Policy | Storage Tier for Write | Fallback Tier for Write | | ||
| | --- | --- | --- | | ||
| | Hot | SSD | DISK | |
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Is this the final list of desired/planned storage policies? Wouldn't we like to implement policies like in HDFS - https://hadoop.apache.org/docs/r3.4.1/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html ?
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Yes, we only support these three simple storage policies current, we can extend it in the future.
| The relation of Storage Policy, Storage Type and Storage Tier | ||
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| - The storage policy is the property of key/bucket/ prefix (Managed by OM); | ||
| - The storage tier is the property of Pipeline and Container (Managed by SCM); |
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Will we deal with the storage tier as an entry of the cluster topology?
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What does “deal with as a cluster topology” mean?
Storage Tier is the property of Pipeline and Container, when we create the key we will select the matched Storage Tier Pipeline and Container based on the key Storage Policy.
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I meant org.apache.hadoop.hdds.scm.net.NodeSchema. Will the Storage Tier (aka rack of specific storage volumes) become a part of the network topology
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Storage Tier is more like the ReplicationConfig, will be a independent fields in ContainerInfo and Pipeline
| ## SCM Pipeline / ContainerReplica Management and Block Allocation | ||
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| - Pipeline needs to add tier-related fields to distinguish between different tiers of Pipelines. | ||
| - For Pipelines tier: |
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The current implementation of the background pipeline creator creates a limited list of RATIS/THREE-pipelines per datanode. The design doc proposes to deal with specific pipelines for different storage policies. Is there any proposal doc on how we gonna deal with the limitation mentioned earlier? (How should we deal with the distribution of the pipelines of different types: 30% per storage tire or some other option? What if the pipelines of one of the storrage tire will not be used?)
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The count limit for current Pipeline count will be extend to each storage tier, so in the extreme condition, there will be three times Pipeline in a cluster.
But in the actual situation, there may not be so many Pipelines, because a Pipeline may support multiple tiers, such as DISK and SSD, because there may be both SSD and DISK type Volume in a Datanode machine.
And the background Pipeline creator will check the current cluster's Volume type, if a cluster has only SSD Volume, the background Pipeline will create a Pipeline with only SSD Tier type.
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@xichen01 is there an understanding of the time frame for the functionality to be implemented? I'd start creating the JIRA tickets and implementing them |
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@xichen01 @kerneltime @sodonnel, could you help somehow to force the review of the design doc? The feature is very needed, and I would gladly start implementation. |
What changes were proposed in this pull request?
Design storage policy for for Ozone. Please comment inline on the markdown document to ask questions and post feedback. Switch to
Rich Diffmode for smoother reading.What is the link to the Apache JIRA
https://issues.apache.org/jira/browse/HDDS-11233
How was this patch tested?
N/A