FAQs

These are known and frequently asked questions about SkyWalking. We welcome you to contribute here.

Design

• Why does SkyWalking use RPC(gRPC and RESTful) rather than MQ as transport layer by default?
• Why is Clickhouse or Loki or xxx not supported as a storage option?

Compiling

• Protoc plugin fails in maven build
• Required items could not be found when importing project into Eclipse
• Maven compilation failure with error such as python2 not found
• Compiling issues on Mac’s M1 chip

Runtime

• New ElasticSearch storage option explanation in 9.2.0
• Version 9.x+ upgrade
• Elasticsearch exception type=version_conflict_engine_exception since 8.7.0
• Version 8.x+ upgrade
• Why do metrics indexes with Hour and Day precisions stop updating after upgrade to 7.x?
• Version 6.x upgrade
• Why are there only traces in UI?
• Tracing doesn’t work on the Kafka consumer end
• Agent or collector version upgrade, 3.x -> 5.0.0-alpha
• EnhanceRequireObjectCache class cast exception
• ElasticSearch server performance issues, including ERROR CODE:429
• IllegalStateException when installing Java agent on WebSphere 7
• “FORBIDDEN/12/index read-only / allow delete (api)” appears in the log
• No data shown and backend replies with “Variable ‘serviceId’ has coerced Null value for NonNull type ‘ID!'"
• Unexpected endpoint register warning after 6.6.0
• Use the profile exporter tool if the profile analysis is not right
• Compatibility with other javaagent bytecode processes
• Java agent memory leak when enhancing Worker thread at Thread Pool
• Thrift plugin

UI

• What is VNode? And why does SkyWalking have that?