micro/go-micro · info

ErrNotFound

ErrNotFound

Error message

not found

What it means

model.ErrNotFound is the sentinel the model package returns when a queried record does not exist (service rows, registry entries, etc.). Callers should compare with errors.Is(err, model.ErrNotFound) to distinguish 'no such record' from real failures.

Source

Thrown at model/model.go:11

// Package model is an interface for structured data storage with schema awareness.
package model

import (
	"context"
	"errors"
)

var (
	// ErrNotFound is returned when a record doesn't exist.
	ErrNotFound = errors.New("not found")
	// ErrDuplicateKey is returned when a record with the same key already exists.
	ErrDuplicateKey = errors.New("duplicate key")
	// ErrNotRegistered is returned when a table has not been registered.
	ErrNotRegistered = errors.New("table not registered")
	// DefaultModel is the default model.
	DefaultModel Model = NewModel()
)

// Model is a structured data storage interface.
type Model interface {
	// Init initializes the model.
	Init(...Option) error
	// Register registers a struct type as a table.
	Register(v interface{}, opts ...RegisterOption) error
	// Create inserts a new record. Returns ErrDuplicateKey if key exists.
	Create(ctx context.Context, v interface{}) error
	// Read retrieves a record by key into v. Returns ErrNotFound if missing.
	Read(ctx context.Context, key string, v interface{}) error

View on GitHub (pinned to 24529f1404)

Solutions

1. Check errors.Is(err, model.ErrNotFound) and handle it as an expected 'absent' outcome, not a crash.
2. Verify the record key/name and that the service was registered before lookup.
3. Retry the lookup with backoff if the record may appear shortly (eventual consistency).
4. Seed required records in tests before the code under exercise reads them.

Example fix

// before
svc, err := reg.GetService("foo")
if err != nil { return err } // crashes on 'not found'
// after
svc, err := reg.GetService("foo")
if errors.Is(err, model.ErrNotFound) { return nil // treat as absent
}
if err != nil { return err }

null

func isNotFound(err error) bool { return errors.Is(err, model.ErrNotFound) }

svc, err := reg.GetService(name)
switch {
case errors.Is(err, model.ErrNotFound):
    return nil, nil // absent is expected
case err != nil:
    return nil, err
}

When it happens

Trigger: Reading a service by name that was never created or was deleted; registry next/Load iterating a table where the requested key is absent; a stale cache referencing a removed service.

Common situations: Race between service deregistration and lookup; typos in service names; querying before registration completed; tests asserting on services not seeded in the store.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

• ErrDuplicateKey
• ErrNotRegistered
• agent: checkpointed run not found
• ErrPoolExhausted
• ErrPoolClosed

AI-assisted analysis of micro/go-micro@24529f1404 (2026-09-01). Data as JSON: /api/errors/a0353dd4ca50fdb6. Report an issue: GitHub.