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【Design Pattern】Microservices - Health Check Pattern
Context
Sometimes a service instance can be incapable of handling requests yet still be running. For example, it might have ran out of database connections. When this occurs, the monitoring system should generate a alert. Also, the load balancer or service registry should not route requests to the failed service instance.
...【Design Pattern】Microservices - Circuit Breaker Pattern
Background
In Electrical or Electornics domain, a circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit. Its basic function is to interrupt current flow after a fault is detected. It can then be reset to resume normal operation after the fault is solved.
Similarly to protect our microservices from an excess of requests, it’s better to interrupt communication between the front-end and the back-end as soon as a recurring fault has been detected in the back-end.
In his excellent book Release It, Michael Nygard popularized the Circuit Breaker pattern to prevent this kind of catastrophic cascade.
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【Golang】Code Review
Summary
-
Use goimports to standardise imports
- a superset of
gofmtwhich additionally adds (and removes) import lines as necessary.
- a superset of
-
godoc
-
gofmt
-
go lint
Flow
Indent Error Flow
Try to keep the normal code path at a minimal indentation, and indent the error handling, dealing with it first. This improves the readability of the code by permitting visually scanning the normal path quickly. For instance, don’t write:
if err != nil {
// error handling
} else {
// normal code
}
