VictoriaMetrics Observability Blog

Blog posts

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Understanding Go's sync.Map from API to Hash Trie

  Go’s sync.Map now uses a hash trie. This article builds the implementation from a normal map, then explains lock-free reads, fine-grained writer locking, collisions, retries, deletion, Clear, Range, and the trade-offs against map plus RWMutex.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.Once is Simple... Does It Really?

  The sync.Once is probably the easiest sync primitive to use, but there’s more under the hood than you might think. It’s also a good opportunity to understand how it works by juggling both atomic operations and mutexes.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.Map: The Right Tool for the Right Job

  Go’s sync.Map isn’t a magic bullet for all concurrent map needs. It’s got some good tricks up its sleeve, like handling reads without locking, but it’s not always the best choice. This article dives into how sync.Map works under the hood, from its two-map system to the bottom line of expunged entries.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go Singleflight Melts in Your Code, Not in Your DB

  What singleflight does is ensure that only one of those goroutines actually runs the operation, like getting the data from the database. It allows only one ‘in-flight’ (ongoing) operation for the same piece of data (known as a ‘key’) at any given moment.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.Cond, the Most Overlooked Sync Mechanism

  In Go, sync.Cond is a synchronization primitive, though it’s not as commonly used as its siblings like sync.Mutex or sync.WaitGroup. That said, as a Go engineer, you don’t really want to find yourself reading through code that uses sync.Cond and not have a clue what’s going on.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.WaitGroup and The Alignment Problem

  When we’re spinning off many goroutines to do their thing, we want to keep track of them so that the main goroutine doesn’t just finish up and exit before everyone else is done. That’s where the WaitGroup comes in. Each time one of our goroutines wraps up its task, it lets the WaitGroup know.

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.Pool and the Mechanics Behind It

• 

  • Go @ VictoriaMetrics
  • Open Source Tech

  Go sync.Mutex: Normal and Starvation Mode

  Mutex in Go has two main flows: Lock and Unlock and 2 modes: Normal and Starvation Mode. The state field of mutex is a 32-bit integer that represents the current state, it’s divided into multiple bits that encode various pieces of information about the mutex.