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Posted to dev@bookkeeper.apache.org by "jiraposter@reviews.apache.org (JIRA)" <ji...@apache.org> on 2012/05/10 10:27:49 UTC

[jira] [Commented] (BOOKKEEPER-252) Hedwig: provide a subscription mode to kill other subscription channel when hedwig client is used as a proxy-style server.

    [ https://issues.apache.org/jira/browse/BOOKKEEPER-252?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13272185#comment-13272185 ] 

jiraposter@reviews.apache.org commented on BOOKKEEPER-252:
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https://reviews.apache.org/r/5086/
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Review request for bookkeeper.


Summary
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In some case, we need to hedwig-client as proxy server to provide messaging service to other users.

client -> proxy server 1 -> hedwig
\> proxy server 2 />

when client would connect to either proxy server to receive messages, the proxy server would setup subscription channel to hedwig server.

we just want client to be simple, so when the channel between client and proxy server is broken, client will try to connect to proxy servers thru VIP. it might connect to other proxy server. for example, first time client connects to proxy server 1, but the client found the connection is broken, it connects to proxy server 2. when proxy server 2 tried to setup subscription channel to hedwig, hedwig found that this subscription has existed before occupied by proxy server 1.

the panic here is that proxy server 1 only disconnect old subscription channel only when it detected the channel between client and itself is broken. The detection might be delayed due to several reasons. so it might increment the latency that messages are pushed to real client.

so we try to introduce a subscription mode called CREATE_OR_ATTACH_OR_KILL mode.

when a subscriber use this subscription mode, it would kill old existed subscription channel. when using this subscription mode, we would turn off auto-reconnect functionality in hedwig client and just tell client about the channel disconnected event so client could do its logic when channel is detected.

in order to provide some admin tool for admin guys to debug/operate, we provide ADMIN mode. if a subscriber attach to a subscription using ADMIN mode, its subscription channel would never be killed, then it is safe to guarantee admin operations.


This addresses bug BOOKKEEPER-252.
    https://issues.apache.org/jira/browse/BOOKKEEPER-252


Diffs
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  hedwig-client/src/main/cpp/inc/hedwig/callback.h 5200d5b 
  hedwig-client/src/main/cpp/inc/hedwig/subscribe.h fc8da58 
  hedwig-client/src/main/cpp/lib/channel.cpp ada1e58 
  hedwig-client/src/main/cpp/lib/clientimpl.h 40e063c 
  hedwig-client/src/main/cpp/lib/clientimpl.cpp 712de01 
  hedwig-client/src/main/cpp/lib/data.h d9d2ffd 
  hedwig-client/src/main/cpp/lib/data.cpp 42fa2ad 
  hedwig-client/src/main/cpp/lib/publisherimpl.cpp a421e98 
  hedwig-client/src/main/cpp/lib/subscriberimpl.h 508a495 
  hedwig-client/src/main/cpp/lib/subscriberimpl.cpp 6f7d02e 
  hedwig-client/src/main/cpp/test/subscribetest.cpp f90502c 
  hedwig-client/src/main/cpp/test/util.h 780a466 
  hedwig-client/src/main/java/org/apache/hedwig/client/api/Subscriber.java 972590b 
  hedwig-client/src/main/java/org/apache/hedwig/client/data/PubSubData.java 8460de0 
  hedwig-client/src/main/java/org/apache/hedwig/client/data/TopicSubscriber.java 064cec1 
  hedwig-client/src/main/java/org/apache/hedwig/client/netty/HedwigPublisher.java 603766c 
  hedwig-client/src/main/java/org/apache/hedwig/client/netty/HedwigSubscriber.java 0c8634c 
  hedwig-client/src/main/java/org/apache/hedwig/client/netty/ResponseHandler.java c4affaf 
  hedwig-client/src/main/java/org/apache/hedwig/util/SubscriptionChannelListener.java PRE-CREATION 
  hedwig-protocol/src/main/java/org/apache/hedwig/protocol/PubSubProtocol.java 92f409d 
  hedwig-protocol/src/main/protobuf/PubSubProtocol.proto b845c40 
  hedwig-server/src/main/java/org/apache/hedwig/admin/console/HedwigCommands.java a17f56b 
  hedwig-server/src/main/java/org/apache/hedwig/admin/console/HedwigConsole.java 5da8e16 
  hedwig-server/src/main/java/org/apache/hedwig/server/handlers/SubscribeHandler.java 76e0c14 
  hedwig-server/src/main/java/org/apache/hedwig/server/netty/PubSubServer.java 52089f5 
  hedwig-server/src/main/java/org/apache/hedwig/server/subscriptions/AbstractSubscriptionManager.java ba841af 
  hedwig-server/src/main/java/org/apache/hedwig/server/subscriptions/InMemorySubscriptionManager.java 0fdfad0 
  hedwig-server/src/main/java/org/apache/hedwig/server/subscriptions/ZkSubscriptionManager.java 4d39335 
  hedwig-server/src/test/java/org/apache/hedwig/client/TestPubSubClient.java 08994de 
  hedwig-server/src/test/java/org/apache/hedwig/server/PubSubServerStandAloneTestBase.java 5f6e363 
  hedwig-server/src/test/java/org/apache/hedwig/server/handlers/TestSubUnsubHandler.java d24a86d 
  hedwig-server/src/test/java/org/apache/hedwig/server/subscriptions/StubSubscriptionManager.java 255880b 
  hedwig-server/src/test/java/org/apache/hedwig/server/subscriptions/TestZkSubscriptionManager.java f6d533f 

Diff: https://reviews.apache.org/r/5086/diff


Testing
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Thanks,

Sijie


                
> Hedwig: provide a subscription mode to kill other subscription channel when hedwig client is used as a proxy-style server.
> --------------------------------------------------------------------------------------------------------------------------
>
>                 Key: BOOKKEEPER-252
>                 URL: https://issues.apache.org/jira/browse/BOOKKEEPER-252
>             Project: Bookkeeper
>          Issue Type: New Feature
>    Affects Versions: 4.1.0
>            Reporter: Sijie Guo
>            Assignee: Sijie Guo
>             Fix For: 4.2.0
>
>         Attachments: BK-252.diff
>
>
> In some case, we need to hedwig-client as proxy server to provide messaging service to other users.
> client -> proxy server 1 -> hedwig
>        \> proxy server 2 />
> when client would connect to either proxy server to receive messages, the proxy server would setup subscription channel to hedwig server.
> we just want client to be simple, so when the channel between client and proxy server is broken, client will try to connect to proxy servers thru VIP. it might connect to other proxy server. for example, first time client connects to proxy server 1, but the client found the connection is broken, it connects to proxy server 2. when proxy server 2 tried to setup subscription channel to hedwig, hedwig found that this subscription has existed before occupied by proxy server 1.
> the panic here is that proxy server 1 only disconnect old subscription channel only when it detected the channel between client and itself is broken. The detection might be delayed due to several reasons. so it might increment the latency that messages are pushed to real client.
> so we try to introduce a subscription mode called CREATE_OR_ATTACH_OR_KILL mode.
> when a subscriber use this subscription mode, it would kill old existed subscription channel. when using this subscription mode, we would turn off auto-reconnect functionality in hedwig client and just tell client about the channel disconnected event so client could do its logic when channel is detected.
> in order to provide some admin tool for admin guys to debug/operate, we provide ADMIN mode. if a subscriber attach to a subscription using ADMIN mode, its subscription channel would never be killed, then it is safe to guarantee admin operations.
>  

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