SSUBSCRIBE(3valkey)

✨ SSUBSCRIBE ✨

okay so bestie, we're in the Valkey Command Manual (that's the 3valkey manual, mwah) and today's main character is ssubscribe 💅

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🌸 NAME 🌸

ssubscribe — she sits there and listens for messages published to shard channels. that's it, that's the job 🎧

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🦋 SYNOPSIS 🦋

SSUBSCRIBE shardchannel [shardchannel...]

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💖 DESCRIPTION 💖

So basically, SSUBSCRIBE subscribes the client to the shard channels you name. iconic behavior, no notes 🫶

Now here's the tea ☕ In a Valkey cluster, shard channels get assigned to slots by the same algorithm used to assign keys to slots. Client(s) can subscribe to a node covering a slot — primary or replica — to receive the messages that get published. 👑

And here's the part you gotta remember, bestie: all the specified shard channels need to belong to a single slot to subscribe in a given SSUBSCRIBE call. but a client can subscribe to channels across different slots over separate SSUBSCRIBE calls. so like, one slot per call, k? 🎀

For more info about sharded Pub/Sub, go peek at valkey-pubsub(7) Sharded Pub/Sub. iykyk 📚

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🌈 REPLY 🌈

When it works, this command doesn't return anything. instead, for each shard channel, one message gets pushed as a confirmation that the command succeeded — and the first element of that message is the string ssubscribe. so cute 🥰

⚠️ heads up: this command can also return a -MOVED redirect. don't panic, it's just Valkey being like "girl, wrong node" 💀

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👑 COMPLEXITY 👑

O(N) where N is the number of shard channels to subscribe to. linear, bestie, we love a predictable queen ✨

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🧚 ACL CATEGORIES 🧚

• @pubsub
• @slow

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⭐ HISTORY ⭐

• Available since: 7.0.0 — she's been serving since day one fr fr 💜

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🍓 EXAMPLES 🍓

> ssubscribe orders
Reading messages... (press Ctrl-C to quit)
1) "ssubscribe"
2) "orders"
3) (integer) 1
1) "smessage"
2) "orders"
3) "hello"

look at her go 🥹 you subscribe to orders, and then boom — an smessage shows up with hello in it. the way that just works. obsessed 🔥

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🌸 SEE ALSO 🌸

• psubscribe(3valkey)
• publish(3valkey)
• pubsub(3valkey)
• pubsub-channels(3valkey)
• pubsub-help(3valkey)
• pubsub-numpat(3valkey)
• pubsub-numsub(3valkey)
• pubsub-shardchannels(3valkey)
• pubsub-shardnumsub(3valkey)
• punsubscribe(3valkey)
• spublish(3valkey)
• subscribe(3valkey)
• sunsubscribe(3valkey)
• unsubscribe(3valkey)

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k bye bestie, go read the other pages, they're all slaying too 💖

this page is brought to you by Valkey 9.0.0, dated 2025-10-21, and the SSUBSCRIBE(3valkey) manual. periodt. 💅