2026-05-22
Capillaries: AMQP 1.0, scalability update
Notable changes since the last scalability testing round:
- AMQP 1.0 support, Capillaries was tested with:
- RabbitMQ 4.3.0
- ActiveMQ Classic 6.2.5
- ActiveMQ Artemis 2.53.0
- more conservative Cassandra LWT use to avoid contention errors (tested with Cassandra 5.0.8)
- sample deployment now uses Ubuntu 26.04
And it's time for the traditional scalability check-up, like in 2025, and in 2024. As usual, the portfolio test was used (996 ARK-inspired stock portfolios with 14,683,696 transactions and 713,800 end-of-month holding records).
| Deployment flavor | AWS instance | 4 Cassandra nodes | 8 Cassandra nodes | 16 Cassandra nodes | 32 Cassandra nodes | Cassandra | Daemon | Bastion/RabbitMQ/Prometheus | Total cores | Hourly cost | Total cores | Hourly cost | Total cores | Hourly cost | Total cores | Hourly cost |
|---|---|---|---|---|---|---|---|---|---|---|---|
| aws.arm64.c7g.8 | c7gd.2xlarge | c7g.large | c7g.large | 42 | $1.8141 | 82 | $3.5557 | 162 | $7.0389 | 322 | $14.0053 |
| aws.arm64.c7g.16 | c7gd.4xlarge | c7g.xlarge | c7g.large | 82 | $3.5557 | 162 | $7.0389 | 322 | $14.0053 | ||
| aws.arm64.c7g.32 | c7gd.8xlarge | c7g.2xlarge | c7g.large | 162 | $7.0385 | 322 | $14.0045 | ||||
| aws.arm64.c7g.64 | c7gd.16xlarge | c7g.4xlarge | c7g.large | 322 | $14.0045 |
| Deployment flavor | Cassandra node cores | Cassandra nodes | Run time, s | Cost of run |
|---|---|---|---|---|
| aws.arm64.c7g.8 | 8 | 4 | 903 | $0.46 |
| 8 | 497 | $0.49 | ||
| 16 | 298 | $0.58 | ||
| 32 | 182 | $0.71 | ||
| aws.arm64.c7g.16 | 16 | 4 | 441 | $0.44 |
| 8 | 248 | $0.48 | ||
| 16 | 160 | $0.62 | ||
| aws.arm64.c7g.32 | 32 | 4 | 259 | $0.51 |
| 8 | 144 | $0.56 | ||
| aws.arm64.c7g.64 | 64 | 4 | 151 | $0.59 |
While overall performance numbers show some improvement (probably, thanks to the Cassandra LWT-related changes), scalability patterns remain largely unchanged.