Thank you vongosling for giving the deep insight of the next-era architecture,
I will break down the rip to seprate sub-tasks, if anyone is interested, please
join us and make it come true.
At 2021-04-23 18:42:37, "vongosling" <[email protected]> wrote:
+1
Thanks veritas follow-up the community and we have talked about Streaming
Tiered Storage Optimize, which is the subparts of the RocketMQ 5. Undoubtedly,
achieving this will be a very challenging task. and I hope the whole R&D will
be more open. If you're interested, please don't hesitate to support it and
join in. I believe veritas has a clear implementation plan waiting for more
guys to join this improvement program.
veritas <[email protected]> 于2021年4月23日周五 下午12:31写道：
RIP 20 Streaming Tiered Storage Optimize
I noticed that the community was designing the next-generation architecutre a
log time ago.After chatting with some guys in the community, I hope to evolve
the design of this architecture and implement it. Thanks for the communication
and guidance given by vongosling. Interested guys are welcome to bread down and
complete architecture evolution in the cloud native era. For detail,
https://github.com/apache/rocketmq/wiki/RIP-20-Streaming-Tiered-Storage-Optimize
Status
Current State: Proposed
Authors: [email protected]
Shepherds: [email protected]
Mailing List Discussion: [email protected]
Pull Request: #PR_NUMBER
Released: <released_version>
Correlations: RIP-18 Metadata management architecture upgrade，Thought of The
Evolution of The Next Decade Architecture for RocketMQ
Background & Motivation
As user business increase ten times at peek times, such as breaking event
happens/shopping festival, and decrease after the peek time to regular, which
may lead to some issues
We have to expand brokers resource in case of storage capacity bottleneck.
We have to expand storage capacity in case of broker cpu bottleneck.
After expand brokers/storage, we cant shrink these resources, which lead 9
times resource waste.
Benchmark test dledger broker-cluster, when leader reach cpu bottleneck,
follower only utilize 10% of cpu resource.
If store one topic 1 year messages, all topics store 1 year
If store one topic 1 year, local storage is expensive
If 1 queue consume 100 times, lead to the leader node bottleneck, while other
node idle
When create new queues, it may choose the busiest broker
Goals
What problem is this proposal designed to solve?
Implement the next generation rocketmq architechture, make the boundaries of
compute and storage layer specific, support stream and tiered storage.
Non-Goals
What problem is this proposal NOT designed to solve?
We will not directly implement multi-raft protocol on RocketMQ.
Are there any limits of this proposal?
Nothing specific.
Changes
Architecture
New architecture graph:
broker
Make clear compute and storage layer interface, focus on compute logic, such as
transaction, delay, filter
Handle produce/consume/admin(rocketmq_protocol) api
Stateless
Use the state-of-the-art Angelia rpc call storage read/write api
Support dynamic add and shrink broker node
Support read replica customized, crack hot queue read imblance problem
storage cluster
Implement storage api for compute node
Multi-raft implement
Support hdfs/S3/GCP
Support dynamic add and shrink storage node
Storage support multi-tenant, like 100w queue
Support topic-level retention time
nameserver cluster
Hash(queue) to a assigned raft group, which broker determine to call the
queue-leader node
Detect storage node failure, notify to broker update queueTostorageNode map
Implement a intellgent module, which use machine learning to decide new queue
assign to which node, and detect unhealthy node.
Angelia
Support multi communication protocol such as tcp, http2
Support multi serilization protocol such as json, Avro
compute and store decouple
compute layer
SendMessageProcessor#asyncSendMessage
this.brokerController.getMessageStore().asyncPutMessage(msgInner);
storage layer
DefaultMessageStore#putMessage
1）commitLog storage
CommitLog#asyncPutMessage
mappedFile.appendMessage(msg, this.appendMessageCallback);
2）Dledger storage
DLedgerCommitLog#asyncPutMessage
#io.openmessaging.storage.dledger.DLedgerServer
dLedgerServer.handleAppend(request);
dLedgerStore.appendAsLeader(dLedgerEntry);
return dLedgerEntryPusher.waitAck(resEntry, false);
3）5.0 seperate storage
SeperateStorage#asyncPutMessage
client:appendMessage() #wait for leader and follower write half nodes
Message Store
Public interface MessageStore {
#basic api
putMessage(final MessageExtBrokerInner msg)
flush()
getMessage(final long offset, final int size)
...
#startup and cache for storage node
load()
...
#failover
recover(long maxPhyOffsetOfConsumeQueue)
...
#manage api
getMaxOffset()
...
for si
Compatibility, Deprecation, and Migration Plan
Are backward and forward compatibility taken into consideration?
the old producer/consumer/admin protocol not change, remains backward compatible
Are there deprecated APIs?
Remove deprecated pull consumer apis.
Rejected Alternatives
How does alternatives solve the issue you proposed?
Use bookkeeper as stream storage engine
Pros and Cons of alternatives
The advantages and disadvantages of using bookkeeper are as follows
Advantage: Simple implementation and short development cycle
Disadvantages: bookkeeper use zookkeeper store ledger metadata, The
introduction of third-party components requires maintenance of two systems, add
maintaince complexity
Why should we reject above alternatives?
The introduction of third-party components is always avoided by RocketMQ, so
the proposal of using bookkeeper(which depends zookkeeper) as metadata storage
is not adopted.
--
Best Regards :-)
