Session Backends¶

Memory Backend¶

The memory backend stores sessions in-process. Ideal for development and single-server deployments.

import (
    "github.com/plexusone/omnistorage-core/session"
    sessionmemory "github.com/plexusone/omnistorage-core/session/backend/memory"
)

cfg := session.Config{
    MaxSessionSize:  1024 * 1024,
    DefaultTTL:      24 * time.Hour,
    CleanupInterval: 5 * time.Minute,
}

// Without controls (raw store)
store := sessionmemory.New(cfg)

// With controls (recommended)
store := sessionmemory.NewWithControls(cfg)

Characteristics:

Zero external dependencies
Automatic cleanup of expired sessions
User index for efficient DeleteByUserID
Not persistent across restarts
Not distributed (single-server only)

KVS Backend¶

The KVS backend adapts any kvs.ListableStore implementation for session storage. This enables Redis, SQLite, or custom backends.

With Redis¶

import (
    "github.com/plexusone/omnistorage-core/session"
    sessionkvs "github.com/plexusone/omnistorage-core/session/backend/kvs"
    kvsredis "github.com/plexusone/omnistorage-core/kvs/backend/redis"
)

// Create Redis KVS backend
redisStore, err := kvsredis.New(kvsredis.Config{
    URL:       "redis://localhost:6379",
    KeyPrefix: "myapp:session:",
})
if err != nil {
    return err
}

// Create session store with controls
cfg := session.Config{
    MaxSessionSize:  1024 * 1024,
    DefaultTTL:      24 * time.Hour,
    CleanupInterval: 5 * time.Minute,
    KeyPrefix:       "session:",
}

store := sessionkvs.NewWithControls(redisStore, cfg)

Redis Characteristics:

Distributed across multiple servers
Automatic TTL expiration via Redis EXPIRE
Persistent across restarts
User index cleanup runs periodically

Key Structure¶

The KVS backend uses the following key structure:

{prefix}{session_id}           → Session JSON
{prefix}user:{user_id}         → JSON array of session IDs

Example with session: prefix:

session:abc123def456           → {"id":"abc123def456","user_id":"..."}
session:user:550e8400-e29b...  → ["abc123def456","xyz789ghi012"]

Custom Backend¶

Implement the session.Store interface to create a custom backend:

type Store interface {
    Create(ctx context.Context, session *Session) error
    Get(ctx context.Context, id string) (*Session, error)
    Update(ctx context.Context, session *Session) error
    Delete(ctx context.Context, id string) error
    DeleteByUserID(ctx context.Context, userID string) (int, error)
    Touch(ctx context.Context, id string) error
    Close() error
}

Wrap your implementation with controls:

store := session.WithControls(myCustomStore, cfg,
    session.WithLogger(logger),
    session.WithViolationHandler(handler),
)

Backend Comparison¶

Feature	Memory	KVS+Redis	KVS+SQLite
Distributed	No	Yes	No
Persistent	No	Yes	Yes
TTL Support	Manual	Native	Manual
Dependencies	None	Redis	SQLite
Best For	Dev/Test	Production	Edge/Embedded