53 lines
2.2 KiB
Markdown
53 lines
2.2 KiB
Markdown
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---
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title: "Storage Container Manager"
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date: "2017-09-14"
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weight: 3
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summary: Storage Container Manager or SCM is the core metadata service of Ozone. SCM provides a distributed block layer for Ozone.
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---
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<!---
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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Storage container manager provides multiple critical functions for the Ozone
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cluster. SCM acts as the cluster manager, Certificate authority, Block
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manager and the replica manager.
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{{<card title="Cluster Management" icon="tasks">}}
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SCM is in charge of creating an Ozone cluster. When an SCM is booted up via <kbd>init</kbd> command, SCM creates the cluster identity and root certificates needed for the SCM certificate authority. SCM manages the life cycle of a data node in the cluster.
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{{</card>}}
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{{<card title="Service Identity Management" icon="eye-open">}}
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SCM's Ceritificate authority is in
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charge of issuing identity certificates for each and every
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service in the cluster. This certificate infrastructre makes
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it easy to enable mTLS at network layer and also the block
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token infrastructure depends on this certificate infrastructure.
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{{</card>}}
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{{<card title="Block Management" icon="th">}}
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SCM is the block manager. SCM
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allocates blocks and assigns them to data nodes. Clients
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read and write these blocks directly.
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{{</card>}}
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{{<card title="Replica Management" icon="link">}}
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SCM keeps track of all the block
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replicas. If there is a loss of data node or a disk, SCM
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detects it and instructs data nodes make copies of the
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missing blocks to ensure high avialablity.
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{{</card>}}
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