| name | distributed-locking-rfc-44 |
| description | RFC-44 compliant distributed locking patterns for Java services. Covers PostgreSQL advisory locks and Redis-based locking, migration workflows, and common patterns. Use when implementing or migrating distributed locking mechanisms.
|
| compatibility | Java projects with PostgreSQL or Redis |
| metadata | {"version":"2.0.0","technology":"java","category":"infrastructure","tags":["java","distributed-locking","rfc-44","postgresql","redis"]} |
Distributed Locking (RFC-44)
RFC-44 compliant distributed locking patterns for Java services.
When to use this skill
- Implementing distributed locking for scheduled jobs
- Migrating from legacy locking mechanisms
- Choosing between PostgreSQL and Redis locking
- Migrating from Fabric8 leader election
- Migrating from incubated in-repo libraries
- When asked to "migrate locks to be RFC-44 compliant"
Skill Contents
Sections
Available Resources
📚 references/ - Detailed documentation
Quick Start
1. Add Dependencies (PostgreSQL)
[versions]
distributed-locking-api = "2.0.0"
distributed-locking-postgres-jooq = "2.0.0"
[libraries]
distributed-locking-api = { module = "com.bitso.commons:distributed-locking-api", version.ref = "distributed-locking-api" }
distributed-locking-postgres-jooq = { module = "com.bitso.commons:distributed-locking-postgres-jooq", version.ref = "distributed-locking-postgres-jooq" }
2. Create Configuration Bean
@Configuration
public class DistributedLockConfiguration {
@Bean
DistributedLockManager<Long> distributedLockManager(
@Qualifier("write-dslcontext") DSLContext dslContext) {
return new JooqPostgresSessionDistributedLockManager(dslContext);
}
}
3. Use in Scheduled Jobs
@Scheduled(cron = "${job.cron:-}", zone = "UTC")
public void scheduledJob() {
try (var lock = distributedLockManager.tryLock("job-lock")) {
if (!lock.acquired()) {
log.info("Job already running on another instance");
return;
}
doWork();
}
}
Implementation Options
RFC-44 supports two valid locking implementations:
| Implementation | When to Use |
|---|
| PostgreSQL Advisory Locks (Default) | Services with PostgreSQL available |
| Redis Locking (Allowed) | Services without PostgreSQL, or with justified Redis use case |
Important: Redis-based locking is NOT deprecated. It is explicitly supported per RFC-44.
Common Patterns
Try-with-resources Pattern
try (var lock = distributedLockManager.tryLock("lock-key")) {
if (!lock.acquired()) {
return;
}
executeTask();
}
Vavr Pattern
Try.withResources(() -> distributedLockManager.tryLock("lock-key"))
.of(lock -> Option.of(lock)
.filter(DistributedLock::acquired)
.onEmpty(() -> log.info("Lock not acquired"))
.peek(l -> doWork()));
References
Related Rules
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