Fallacies Of Distributed Gomputing

Michael Hausenblas

There are any fallacies in distributed computing. This stuff will bite you sooner or later. For each fallacy, I address the problem with a general solution and a Go specific solution.

1. The network is reliable

In general: timeouts, error handling, retry logic.

Go language &stdlib:

Beyond stdlib:

2. Latency is zero

In general: cancelation, partial results

Go language & stdlib:

  • context.WithCancel
  • encoding/json.Decoder.Decode(Stream)

Beyond stdlib:

3. Bandwidth is infinite

In general: CDNs, protobuf rather than JSON

Go: golang/protobuf

4. The network is secure

In general: SSL/TLS, digital signatures, checksums

For go: crypto/tls, crypto/rsa, crypto/sha512, crypto/x509

Beyond stdlib:

5. Topology doesn't change

In general: DNS vs. IP addresses, TTL

In Go: be aware of the pure Go resolver

6. There is one administrator

In general: auditing, role-based access, immutability

Go language & stdlib:

Beyond stdlib:

7. Transport cost is zero

In general: cost of (un)marshalling

In Go stdlib:

Beyond stdlib:

8. The network is homogeneous

In general: interoperability on all levels.

In Go: broad and well-tested stdlib

Beyond stdlib:

Overview case studies

I'll be covering five open source distributed systems.

All stats taken on 2017-07-06:


Used cloc to generate raw stats:



Kubernetes.io is a container orchestration platform.

  • Google initiated, opinionated, some 70% market share - Like the kernel for a cluster operating system
- Initially was depending on Docker (now: CRI-O)
- Bring your own SDN, minimal core + plugins

Fallacies covered:

  • The network is reliable.

  • The network is secure.

  • Transport cost is zero.

Architecture overview:



Consul is a tool for service discovery and configuration

  • Not one thing but many things to many people
  • Can provide service discovery (microservices architecture)
  • Can be used as a key-value store
  • Uses Serf lib as gossip protocol (manage membership/broadcast messages)

Fallacies covered:

  • Topology doesn't change.

Architecture overview:



etcd is a distributed, reliable key-value store

  • Distributed setup realized via Raft
  • Benchmarked at 10,000 writes/sec
- Exposes HTTP and gRPC interfaces
- Automatic TLS with optional client cert authentication

Fallacies covered:

  • The network is reliable.
  • Bandwidth is infinite.
  • Transport cost is zero.

CockroachDB 23.4

CockroachDB is a distributed SQL database

  • Primary design goals: scalability, strong consistency, survivability
  • Every node in the cluster can act as SQL gateway, mapping and executing SQL statements to key-value operations
  • Uses RocksDB (variant of Google's LevelDB storage lib) for persistence

Fallacies covered:

  • Latency is zero.
  • The network is homogeneous.

Architecture overview:



Minio is an object storage server compatible with Amazon S3 APIs

  • Cloud-native/container-ready objects with up to 5TB in size
  • Storage API covers local storage as well as network storage
  • Uses erasure code algorithm to protect data
  • New: gateway for multi-cloud (Azure, GCS, S3) access

Fallacies covered:

  • The network is reliable
  • Transport cost is zero

Architecture overview:



Some observations from the code reviews carried out in order to prepare this talk:

  • subjectively, the top three types of issues encountered were: timeouts, DNS, and resource exhaustion
  • go doc is awesome; high level of coverage; right incentives such as godoc.org
  • Go best practices, six years in also applies (think: operations)
  • make it possible to replicate test and build pipeline locally
  • ... and also, slightly controversial: Container Assisted Testing


  • Go is a great language for a team to build (complex) distributed systems

  • Go scales: both in the

  • Go is a great language for a team to build (complex) distributed systems

  • Go scales: both in the human dimension and concerning machines

  • Any chance that we're gravitating towards a common lib for 'distributed gomputing'?

Take home message: be aware of the 8 fallacies and how to avoid them!

For complete slides: http://go-talks.appspot.com/github.com/mhausenblas/fallacies-of-distributed-gomputing/main.slide.

Liveblog by Linda Xie (@lindeexie)

screenshot-20 2017-07-14

Michael Hausenblas is a developer advocate for OpenShift and Kubernetes Hat Red Hat. His background is in large-scale data processing and container orchestration. He also contributes to open source software, mainly using Go.

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