[DrainingHash] pulsar-client 4.0.1 with java.lang.ClassNotFoundException

[unicojoyhug]

Hi,

Issue:

Upgrading org.apache.pulsar:pulsar-client from version from 3.3.1 to 4.0.1 - it fails to create the client with ClassNotFoundException as below:

Failed to instantiate [org.apache.pulsar.client.api.PulsarClient]: 
Factory method 'pulsarClient' threw exception with message: org/apache/pulsar/common/policies/data/DrainingHash

Implementation:

I use pulsar-client to create a client to consume events with adding AuthenticationOAuth2.

• privateKey is added with data:application/json;base64,<base64-encoded value> following doc - authentication-types

What I checked:

• checked the source package where it referenced DrainingHashImpl : the import path doesn't contain DrainingHash
• checked where it was found in pulsar repo: DrainingHash interface is found in pulsar-client-admin-api/common
  • maybe it is related to this change? ref: PR - [improve][broker][PIP-379] Add observability stats for "draining hashes"

What I have tried:

• tried to use pulsar-client-all instead to see if I can get these all included, but it failed to find the DrainingHash interface for DrainingHashImpl

Let me know if I need to supply more information or write this to somewhere else.
I'd love to know what I should do to avoid this error.

[lhotari]

You might have multiple versions of the Pulsar client in the classpath. The DrainingHash interface is included in the pulsar-client-admin-api module. One way to resolve this problem is to use the Pulsar BOM (unless you are using Spring Boot). For Spring Boot there's a specific solution.