[KAFKA-7048] NPE when creating connector

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Assignee: Chia-Ping Tsai
• Reporter: Chia-Ping Tsai
• Created: 12/Jun/18 16:39
• Updated: 18/Jun/18 03:28
• Resolved: 18/Jun/18 03:28

Description

KAFKA-6886 introduced the ConfigTransformer to transform the given configuration data. ConfigTransformer#transform(Map<String, String>) expect the passed config won't be null but DistributedHerder#putConnectorConfig call the #transform before updating the snapshot (see below). Hence, it cause the NPE. 

// Note that we use the updated connector config despite the fact that we don't have an updated
// snapshot yet. The existing task info should still be accurate.
Map<String, String> map = configState.connectorConfig(connName);
ConnectorInfo info = new ConnectorInfo(connName, config, configState.tasks(connName),
    map == null ? null : connectorTypeForClass(map.get(ConnectorConfig.CONNECTOR_CLASS_CONFIG)));
callback.onCompletion(null, new Created<>(!exists, info));
return null;

We can add a null check to "configs" (see below) to resolve the NPE. It means we WON'T pass the null configs to configTransformer

public Map<String, String> connectorConfig(String connector) {
    Map<String, String> configs = connectorConfigs.get(connector);
    if (configTransformer != null) { // add a condition "configs != null"
        configs = configTransformer.transform(connector, configs);
    }
    return configs;
}

 

 

Issue Links

• links to: GitHub Pull Request #5202