RPUSH
Syntax
RPUSH key element [element ...]
Time complexity: O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.
ACL categories: @write, @list, @fast
Insert all the specified values at the tail of the list stored at key.
If key does not exist, it is created as empty list before performing the push
operation.
When key holds a value that is not a list, an error is returned.
It is possible to push multiple elements using a single command call just
specifying multiple arguments at the end of the command.
Elements are inserted one after the other to the tail of the list, from the
leftmost element to the rightmost element.
So for instance the command RPUSH mylist a b c will result into a list
containing a as first element, b as second element and c as third element.
Return
Integer reply: the length of the list after the push operation.
Examples
dragonfly> RPUSH mylist "hello"
(integer) 1
dragonfly> RPUSH mylist "world"
(integer) 2
dragonfly> LRANGE mylist 0 -1
1) "hello"
2) "world"
Benchmark
Sustained throughput for RPUSH on a single instance, measured against Redis and Valkey on identical hardware. Higher is better.
| Engine | Throughput | p50 | p99 | p99.9 | Avg Latency |
|---|---|---|---|---|---|
| Dragonfly | 5.99M ops/s | 0.531 ms | 5.922 ms | 11.373 ms | 0.782 ms |
| Valkey | 893.5K ops/s | 5.197 ms | 11.570 ms | 15.476 ms | 5.359 ms |
| Redis | 698.8K ops/s | 6.573 ms | 11.298 ms | 17.824 ms | 6.856 ms |
Methodology
| Hardware | Server: m7g.8xlarge (arm64) · Client: c6gn.8xlarge (arm64) |
| Client | 32 threads, 5 connections, pipeline 30 |
| Dataset | 100M keys, 128B values, uniform key distribution |
| Duration | 300s (10s warmup), 1 trial |
| Measured | 2026-07-29 |
Ran through dfly_bench until throughput stabilized; the reported figure is the median throughput sampled during the run. Harness and raw output: dragonflydb/benchmarking.