What I forgot to consider when changing into
serverless with Lambda
I was infrastructure engineer at a printing company
in Kanazawa until 2020 that did proof-of-concept of
infrastructure using AWS, transferred jobs to East
Co., Ltd. in January 2021.
I am also contributing to JAWS-UG since 2018 as a
core member of the JAWS-UG Kanazawa chapter.
And, I am active as a financial planner (AFP).
My hobbies are running, bowling and grow
What’s Kanazawa Chaptor?
We hold study sessions every month, mainly in
Kanazawa, Ishikawa Prefecture.
We want the following people to join us!
・Interested in AWS
・Want to make more
use of AWS
・Want to find friends
who are using AWS
We held AWS Community Day Kanazawa in 2019!
Understand the pitfalls and countermeasures
in Lambda that can easily realize serverless.
Understand about Lambda cold start and
・Overview of serverless services
・What pit did I fall into?
・What should We do?
Introduction of the contents of this service
・DONGRI which provided by East Co., Ltd. is dictionary application
and can be used from a wide lineup of various dictionaries and
・DONGRI offers iOS, Android, and
Windows versions, and can be used
through multiple devices, and can be
used not only online but also offline.
・One word can be searched through
・Mainly used at school and at home
・Often used during the daytime on weekdays and at night
・Often used all at once in class, so momentary peaks are
likely to occur
Architecture before migration
EC2s to a load
distribute the load
Old architectural challenges
・Not expandable, and the cost of maintaining a redundant
configuration remains high
・ There is a possibility that the service will be stopped in the
event of an AZ failure
(The instance is built only in ap-northeast-1b)
・ High maintenance cost for Windows Server based system
・ It is difficult to maintain the original database in EC2
Reduce maintenance costs by configuring to
scale with a configuration using Lambda and
DocumentDB and migrating to managed
For dictionaries that have not been migrated to
DocumentDB due to the migration transition
period, the request is forwarded to the
conventional system and searched.
・A 502 error occurred during the load test. After
investigating the cause, it was due to exceeding the number
of concurrent executions, which is the default of 1000.
We applied for mitigation
We intended to solve
the problem by applying
for relaxation from 1000
to 5000 simultaneous
executions of accounts!
When I did a server load test, I got a different error. After
investigating the cause, it was found that throttling had occurred.
What should We do?
・Reduce process time
→ Avoid cold start and use Provisioned Concurrrency Setteings
What’s cold start?
What should We do?
・It is important to adopt a configuration that can
・Let's see ”Amazon ECS &
knowledge to handle large-
scale load of Roma Saga
・Understand the characteristics of the
architecture to be adopted
・Consider load testing during PoC
・Read the documentation carefully
・Let's see the use case!