*Motivation*

The getSchema logic in Pulsar proxy handler doesn't handle the case that
the request doesn't have schema version.

*Modification*

- Fix the logic to handle the case that a GetSchema request doesn't have schema version.
- Forward the GetSchemaResponse back to the client

*Tests*

The GetSchema tests in ProxyTest was disabled by mistake. Turn it on.
(cherry picked from commit 676fd71a)

* o.a.p.c.api -> o.a.p.c.protocol

Classes in pulsar-common module were moved to avoid jpms split-package
conflict between the pulsar-client-api and pulsar-common modules.

* o.a.p.c.schema -> o.a.p.c.protocol.schema

Classes in pulsar-common module were moved to avoid jpms split-package
conflict between the pulsar-client-api and pulsar-common modules.

* Support set message size
---

*Motivation*

Currently Pulsar only support 5MB size of messages.But there are many cases will use more than 5MB message
to transfer.
https://github.com/apache/pulsar/wiki/PIP-36%3A-Max-Message-Size

*Modifications*

- Add message size in protocol
- Automaticlly adjust client message size by server

* Use `maxMessageSize` to set `nettyFrameSize` in bookie client
---

*Motivation*

When broker specify a `maxMessageSize` bookie should accept this value as `nettyFrameSize`

*Modifications*

- Use `cnx().getMaxMessageSize`
- Discovery service only redirect so use the constant value `5 * 1024 * 1024` as message size
- Put `MAX_METADATA_SIZE` as constant value in `InternalConfigurationData`

* Use `Commands` to store message setting
---

*Modifications*

- use `Commands` to store default `MAX_MESSAGE_SIZE` and `MESSAGE_SIZE_FRAME_PADDING`
- replace `LengthFieldBasedFrameDecoder` when has set message size
- replace `PulsarDecoder.MaxMessageSize`

* Fix some error

* Fix license header

* Add test and make `ClientCnx.maxMessageSize` static
---

*Motivation*

- Even if the cnx can't use, `maxMessageSize` should be used at compare message size. So it should as a static variable

* fix code style

* Fix license header

### Motivation

Currently, each `ClientCnx` has a blocking queue for the max number of pending lookup requests. By default that ends up using an array of 45K objects. When a single process handles many connections (eg: broker or proxy), that will end up using 200K per connection just for this.

### Modifications

Instead of using the fixed array size, use semaphore and a `ConcurrentLinkedQueue`

* Reduce memory used in ClientCnx for pending lookups

* Fixed semaphore size

Fixes #3655

Master Issue: #3491

### Motivation
add support of Kerberos authentication for proxy

### Modifications
add support of Kerberos authentication for proxy ;
add unit test.

### Verifying this change
Ut passed

This is to implement the mutual auth api discussed in "PIP-30: change authentication provider API to support mutual authentication"
Mainly provide 2 new command CommandAuthResponse and  CommandAuthChallenge in proto, to support it.

* Propagate specific Schema error to client

* Handling new enums in C++

* Fixed formatting

* Separate pulsar client API interfaces in different module

* Added provided protobuf dep

* Fixed build and tests

* Fixed import name

* Fixed AuthenticationTls class name

* Fixed AutoProduceSchema name

* timeout stuck producer/consumer operation request

* address comment

* fix tests

* timer task to check timeouts

* Make proxy advertise protocol version of client to broker

* Revert incorrect change

### Motivation

Fixes #189

When consumer got messages from pulsar, It's difficult to ensure every message can be consume success. Pulsar support message redelivery feature by set acknowledge timeout when create a new consumer. This is a good feature guarantee consumer will not lost messages.

But however, some message will redelivery so many times possible, even to the extent that it can be never stop.

So, It's necessary to support a feature to control it by pulsar. Users can use this feature and customize this feature to control the message redelivery behavior. The feature named Dead Letter Topic.

### Modifications

Consumer can set maximum number of redeliveries by java client.
Consumer can set the name of Dead Letter Topic by java client, It’s not necessary.
Message exceeding the maximum number of redeliveries should send to Dead Letter Topic and acknowledged automatic.

### Result

If consumer enable future of dead letter topic. When Message exceeding the maximum number of redeliveries, message will send to the Dead Letter Topic and acknowledged automatic.

* fix some typos

* change Faild to Failed

* add rate limit for client lookup request

* change following comments

* make client keepAliveInterval configurable

* add client builder for config

* change to use TimeUnit

* Schema Registry proto changes

* Infrastructure to store schemas

* A default schema registry implementation

* Add admin api for the schema registry

* Renumber schema fields

* Update Pulsar API with schema changes

* Revert field number change

* Fix merge conflict

* Fix broken merge

* DestinationName has been renamed to TopicName

* Address issues in review

* Add schema type back to proto definition

* Address comments regarding lombok usage

* Remove reserved future enum fields

* regenerate code from protobuf

* Remove unused code

* Add schema version to producer success message

* plumb schema through to producer

* Revert "Add schema version to producer success message"

This reverts commit e7e72f468cf46f1605524a7399520c22763583c9.

* Revert "Revert "Add schema version to producer success message""

This reverts commit 7b902f6bdb1cb054e26577747ff4dd8c326a6248.

* Persist schema on producer connect

* Add principal to schema on publish

* Reformat function for readability

* Remove unused protoc profile

* Rename put on schema registry to putIfAbsent

* Reformat function for readability

* Remove unused protoc profile

* Rename put on schema registry to putIfAbsent

* fix compile errors from parent branch changes

* fix lombok tomfoolery on builder

* plumb hash through and allow lookup by data

* wip

* run tests

* wip: address review comments

* switch underscore to slash in schema name

* blah

* Get duplicate schema detection to work

* Fix protobuf version incompatibility

* fix merge issues

* Fix license headers

* Fix license headers

* Address review

* Fix webservice

* plumb schema from producer to server and back

* Plumb schema through subscriber

* Create and return schema via rest endpoint

* Make DELETE great again

* Clean up imports

* Move resource objects to common package

* Fix licenses

* Update error message for schema registry service

* Remove cruft

* Address review comments

- rename props to properties in GetSchemaResponse
- Use config for ledger parameters

* Address review comments

* Fix license headers

* deal with lombock stuff causing issues

* Resolve conflict

* leverage lookup service to getTopicsOfNamespace, add subscribe pattern method

* change following @matteo's comments

* fix rebase error

* add comments for pattern in builder

* Refactored ClientConfuguration to use ClientConfigurationData shared with ClientBuilderImpl

* Fixed unit tests

* Fixed cloning issue after refactoring

* Fixed another test

* Fixed cloning issues

* Fixes for mock tests

* Fixed refactoring problem in TopicsConsumerImpl

Introduce ActiveConsumerListener for realizing if a consumer is active in a failover subscription group (#1156)

* Introduce ConsumerGroupListener for realizing if a consumer is active in a failover subscription group

* Rename ConsumerGroupListener to ActiveConsumerListener

* Fail subscribe if active consumer listener is provided with non-failover subscription.

* Notify consumer state change only after the cursor is rewinded.

* Address comments

* Rename ActiveConsumerListener to ConsumerEventListener
Use consumer object as identifier for comparison

* Fix test after rebase

* Fix license headers

* Ignore active consumer change command in cpp client

* rename "become" to "became"

* add CommandGetLastMessageId to getlastMessageId of topic

* rebase master, change following comments

* add partition index in GetLastMessageIdResponse

* fix rebase error

* bump proot version to v11

* change following comments

* change following comments2

* change following comments3

* change following comments

* get cnx() first

* Add pluggable authorization service

fix: move FutureUtils to common and fix import

add grantpermission api

take default auth method

pass authData to authorization provider

keep single authorization provider

* fix rebase change

* Add hostname-verification at client tls connection

* add httpclient dep with exclude all + add pem in apache-rat

* add httpclient+commons-logging dep in client-shading and LICENSE

* shade artifacts

* fix: proxy send certs to client for host verification

* Add connection timeout for binary lookup request

* operation timeout

* fix test