Vadym KazulkinIntroduction
In the part 2 of our article series we explored how to develop and deploy pure Lambda function (without using any frameworks like Spring Boot 3) with Custom Runtime containing GraalVM Native Image with GraalVM 21 runtime and in the part 3 we measured the performance (cold and warm start times) of the Lambda function with 1024 MB of memory using this approach.
In this article we'll measure cold and warms starts of the Lambda with different memory settings between 256 and 1536 MBs to explore the tradeoff between cost and performance.
Measuring cold and warm starts of Lambda function with Custom Runtime containing GraalVM Native Image with different memory settings
We'll re-use exact the same experiment described in the part 3 of this article series but with different memory settings between 256 and 1536 MBs.
Here are results of the experiment:
Cold (c) and warm (m) start time in ms:
| Memory setting | c p50 | c p75 | c p90 | c p99 | c p99.9 | c max | w p50 | w p75 | w p90 | w p99 | w p99.9 | w max |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 256 MB | 822.74 | 833.50 | 845.25 | 923.88 | 952.96 | 953.84 | 4.04 | 4.59 | 5.47 | 18.55 | 137.10 | 471.76 |
| 512 MB | 620.04 | 621.40 | 657.70 | 705.37 | 727.57 | 727.97 | 4.16 | 4.65 | 5.46 | 14.32 | 64.54 | 229.29 |
| 768 MB | 561.63 | 574.11 | 589.82 | 628.15 | 633.83 | 634.23 | 4.23 | 4.73 | 5.55 | 13.01 | 42.31 | 203.22 |
| 1024 MB | 525.77 | 532.12 | 542.32 | 632.56 | 635.73 | 636.11 | 4.16 | 4.69 | 5.46 | 12.30 | 37.25 | 211.83 |
| 1280 MB | 515.37 | 524.20 | 539.08 | 577.57 | 624.39 | 624.52 | 4.23 | 4.77 | 5.64 | 12.80 | 34.67 | 126.97 |
| 1536 MB | 504.16 | 516.40 | 528.93 | 548.86 | 628.15 | 628.31 | 4.26 | 4.73 | 5.55 | 12.70 | 44.03 | 105.46 |
Conclusion
In this article measured cold and warms starts of the pure Lambda function having the memory setting between 256 and 1536 MB using Custom Runtime containing GraalVM Native Image with GraalVM 21 runtime.
We observe that warm start times are very close for each other also for setting lower memory like 256 or 512 MBs and difference is mainly visible for the high percentiles (>= p90). The cold start times are quite high for 256 and 512 MBs and starting from 768 MBs very decrease only a bit by giving Lambda more memory without any noticeable difference for memory greater than 1024 MB. Depending on your performance requirements you can give Lambda less memory than 1024 MBs as we initial gave in the sample application and have a very good price performance trade off with 768 MB or even a bit less memory.
At the time of publishing also newer versions became available (like GraalVM 23 runtime), so you case make the version changes and re-compile GraalVM Native image following the instructions from the part 2 of the series and re-measure the performance.
