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Databases · head to head

Memcached vs Apache Pulsar

Memcached logo

Memcached

Databases

Distributed memory object caching system

From
Free
Rated
-
Full reviewWebsite
Apache Pulsar logo

Apache Pulsar

Databases

Cloud-native messaging and streaming with separated storage

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Memcached no persistence at all: restart a node and its cache is gone, which every design must assume; Apache Pulsar more components than Kafka: brokers, BookKeeper and ZooKeeper each need operating
  • They diverge on capability: Memcached covers In-memory key-value cache, Apache Pulsar covers Separated storage.

Where they differ

Only the attributes on which Memcached and Apache Pulsar actually diverge.

Attributes where Memcached and Apache Pulsar differ
AttributeMemcachedApache Pulsar
Pricing modelOpen source, no licence fee; managed cloud billed separatelyOpen source, no licence fee
PlatformsLinux, macOS, Windows, Docker, Self-hostedLinux, Docker, Kubernetes, Self-hosted

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Databases).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Memcached

  • In-memory key-value cache
  • Multithreaded
  • Client-side sharding
  • Predictable memory use

Only in Apache Pulsar

  • Separated storage
  • Queuing and streaming
  • Built-in multi-tenancy
  • Geo-replication

What people use each for

The jobs each tool is most often brought in to do.

Memcached

  • Caching expensive database query results to cut loadnot Apache Pulsar
  • Session storage where losing sessions on restart is acceptablenot Apache Pulsar
  • Fronting an API whose responses are costly and change slowlynot Apache Pulsar

Apache Pulsar

  • Platforms needing both work queues and replayable streams without running two systemsnot Memcached
  • Multi-tenant messaging where isolation between teams is a requirementnot Memcached
  • Deployments where storage and traffic grow at genuinely different ratesnot Memcached

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Memcached

  • No persistence at all: restart a node and its cache is gone, which every design must assume
  • No replication or failover, so losing a node loses that share of the cache
  • Only simple key-value, with none of the lists, sorted sets or streams Redis offers
  • Values are capped at 1MB by default, which surprises teams caching large documents

Apache Pulsar

  • More components than Kafka: brokers, BookKeeper and ZooKeeper each need operating
  • Correspondingly harder to run well, and the expertise is rarer than Kafka expertise
  • A much smaller ecosystem of connectors, tooling and hiring pool than Kafka
  • The architectural advantages only pay off at a scale most deployments never reach

Pricing, plan by plan

Memcached

Free
  • MemcachedFree
    • Full functionality
    • Self-hosted
    • No usage limits

Apache Pulsar

Free
  • Apache PulsarFree
    • Full functionality
    • No usage limits
    • Community support

Which should you pick?

Choose Memcached if

  • You need in-memory key-value cache.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Self-hosted.
  • You also want multithreaded.
Memcached review

Choose Apache Pulsar if

  • You need separated storage.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want queuing and streaming.
Apache Pulsar review

Questions people ask

Is Memcached or Apache Pulsar better?
Neither clearly leads. Memcached starts at Free and Apache Pulsar at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Memcached or Apache Pulsar?
Memcached starts at Free and Apache Pulsar at Free.
Does Memcached or Apache Pulsar run on more platforms?
Memcached runs on Linux, macOS, Windows, Docker, Self-hosted. Apache Pulsar runs on Linux, Docker, Kubernetes, Self-hosted.
Can I use Memcached for free?
Both have a free tier, so you can try either at no cost before committing.
What is Memcached best used for?
Memcached is most often used for caching expensive database query results to cut load, session storage where losing sessions on restart is acceptable, fronting an api whose responses are costly and change slowly. Of those, caching expensive database query results to cut load and session storage where losing sessions on restart is acceptable are not what Apache Pulsar is typically brought in for.
What can Memcached do that Apache Pulsar cannot?
Memcached covers In-memory key-value cache, Multithreaded, Client-side sharding, Predictable memory use. Apache Pulsar covers Separated storage, Queuing and streaming, Built-in multi-tenancy, Geo-replication.

Answered from the vendors’ own pages

Memcached: Is Memcached free?

Yes, open source with no licence fee.

Apache Pulsar: Is Apache Pulsar free?

Yes, open source under the Apache Software Foundation.

Memcached: Memcached or Redis?

Memcached is a pure cache: simpler, multithreaded and very predictable. Redis adds persistence, replication and rich data structures, which is why it is the default choice unless you specifically want a cache and nothing more.

Apache Pulsar: Pulsar or Kafka?

Pulsar separates storage from compute and covers queuing and streaming in one system. Kafka has a far larger ecosystem and hiring pool. Most teams should have a specific reason before choosing Pulsar.

Memcached: Does Memcached persist data?

No. Everything is in memory and lost on restart, by design.

Apache Pulsar: Why does separated storage matter?

Brokers hold no data, so adding or replacing one requires no rebalancing, and storage can grow without adding serving capacity.

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