Lambdaから大量にDSQLに接続してエラー発生有無を確認してみた

import { Client } from 'pg'
import { DsqlSigner } from '@aws-sdk/dsql-signer';

const region = process.env.AWS_REGION;
const clusterEndpoint = `${process.env.DSQL_CLUSTER_IDENTIFIER}.dsql.${region}.on.aws`
const signer = new DsqlSigner({
      hostname: clusterEndpoint,
      region,
    });
const token = await signer.getDbConnectAdminAuthToken();
const getNewClient = () => (
  new Client({
      host: clusterEndpoint,
      port: 5432,
      database: 'postgres',
      user: 'admin',
      password: token,
      ssl:true
  })
);
let client = null;
let connected = false;

export const lambdaHandler = async (event, context) => {
  if (!connected) {
    client = getNewClient();
    await client.connect();
    connected = true;
  }
  await client.query(`SELECT pg_sleep(5)`);
  return {
    statusCode: 200,
    body: JSON.stringify({
      message: 'Hello from DSQL!',
    })
  }
};

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Globals:
  Function:
    Timeout: 10
    Tracing: Active
    MemorySize: 1769
  Api:
    TracingEnabled: true
Resources:
  Dsql:
    Type: AWS::DSQL::Cluster
    Properties:
      DeletionProtectionEnabled: false
  DsqlTestFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: hello-world/
      Handler: app.lambdaHandler
      Runtime: nodejs22.x
      Architectures:
      - arm64
      Layers:
        - arn:aws:lambda:us-east-1:615299751070:layer:AWSOpenTelemetryDistroJs:8
      Role: !GetAtt LambdaRole.Arn
      Environment:
        Variables:
          OTEL_NODE_ENABLED_INSTRUMENTATIONS: pg
          AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-instrument
          DSQL_CLUSTER_IDENTIFIER: !Ref Dsql
      Events:
        api:
          Type: Api
          Properties:
            Path: /dsql
            Method: get
  LambdaRole:
      Type: AWS::IAM::Role
      Properties:
        AssumeRolePolicyDocument:
          Version: '2012-10-17'
          Statement:
          - Effect: Allow
            Principal:
              Service:
              - 'lambda.amazonaws.com'
            Action: sts:AssumeRole
        Policies:
        -
          PolicyName: dsql-blog-policy
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
            -
              Effect: "Allow"
              Action:
                - 'dsql:*'
                - "logs:*"
                - "xray:*"
              Resource: '*'

hey -c 1000 -n 1000 https://<API GWのID>.execute-api.us-east-1.amazonaws.com/Prod/dsql

Summary:
  Total:	8.4554 secs
  Slowest:	8.4390 secs
  Fastest:	7.3154 secs
  Average:	7.9864 secs
  Requests/sec:	118.2682

  Total data:	30000 bytes
  Size/request:	30 bytes

Response time histogram:
  7.315 [1]	|
  7.428 [1]	|
  7.540 [6]	|■
  7.652 [3]	|■
  7.765 [73]	|■■■■■■■■■■■■
  7.877 [192]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  7.990 [215]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  8.102 [234]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  8.214 [217]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  8.327 [52]	|■■■■■■■■■
  8.439 [6]	|■

Latency distribution:
  10% in 7.7795 secs
  25% in 7.8664 secs
  50% in 7.9947 secs
  75% in 8.1087 secs
  90% in 8.1809 secs
  95% in 8.2224 secs
  99% in 8.3095 secs

Details (average, fastest, slowest):
  DNS+dialup:	0.5355 secs, 7.3154 secs, 8.4390 secs
  DNS-lookup:	0.0695 secs, 0.0043 secs, 0.1601 secs
  req write:	0.0735 secs, 0.0001 secs, 0.1683 secs
  resp wait:	7.3768 secs, 6.8654 secs, 7.8326 secs
  resp read:	0.0000 secs, 0.0000 secs, 0.0002 secs

Status code distribution:
  [200]	1000 responses

filter ispresent(attributes.db.name)
| stats count(*) as cnt,
min(durationNano / 1000000) as min,
max(durationNano / 1000000) as max,
avg(durationNano / 1000000) as avg,
pct(durationNano / 1000000, 95)  as p95,
pct(durationNano / 1000000, 90)  as p90,
pct(durationNano / 1000000, 50)  as p50
by name

hey -c 7000 -n 250000 -q 1 https://<API GWのID>.execute-api.us-east-1.amazonaws.com/Prod/dsql

Summary:
  Total:	193.5898 secs
  Slowest:	19.6279 secs
  Fastest:	0.0110 secs
  Average:	3.5422 secs
  Requests/sec:	1265.5624

  Total data:	7987410 bytes
  Size/request:	32 bytes

Response time histogram:
  0.011 [1]	|
  1.973 [84408]	|■■■■■■■■■■■■■■■■■■■■■■■■■■
  3.934 [15137]	|■■■■■
  5.896 [128119]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  7.858 [11581]	|■■■■
  9.819 [4061]	|■
  11.781 [1520]	|
  13.743 [78]	|
  15.705 [93]	|
  17.666 [0]	|
  19.628 [1]	|

Latency distribution:
  10% in 0.1668 secs
  25% in 0.5442 secs
  50% in 5.0286 secs
  75% in 5.0340 secs
  90% in 5.6061 secs
  95% in 6.5266 secs
  99% in 9.3013 secs

Details (average, fastest, slowest):
  DNS+dialup:	0.1016 secs, 0.0110 secs, 19.6279 secs
  DNS-lookup:	0.1359 secs, 0.0000 secs, 4.0230 secs
  req write:	0.0358 secs, 0.0000 secs, 4.0838 secs
  resp wait:	3.2332 secs, 0.0109 secs, 19.5949 secs
  resp read:	0.0188 secs, 0.0000 secs, 2.4516 secs

Status code distribution:
  [200]	138759 responses
  [500]	97321 responses
  [502]	8919 responses

Error distribution:
  [1]	Get "https://faawmhbgr0.execute-api.us-east-1.amazonaws.com/Prod/dsql": context deadline exceeded (Client.Timeout exceeded while awaiting headers)

{
  "errorType": "error",
  "errorMessage": "unable to accept connection, rate exceeded",
  "code": "53400",
  "length": 110,
  "name": "error",
  "severity": "FATAL",
  "detail": "Session Id: svtcuhakmrll35mtgjvooj5gzy",
  "stack": [
    "error: unable to accept connection, rate exceeded",
    "    at Parser.parseErrorMessage (/var/task/node_modules/pg-protocol/dist/parser.js:285:98)",
    "    at Parser.handlePacket (/var/task/node_modules/pg-protocol/dist/parser.js:122:29)",
    "    at Parser.parse (/var/task/node_modules/pg-protocol/dist/parser.js:35:38)",
    "    at TLSSocket.<anonymous> (/var/task/node_modules/pg-protocol/dist/index.js:11:42)",
    "    at TLSSocket.emit (node:events:518:28)",
    "    at addChunk (node:internal/streams/readable:561:12)",
    "    at readableAddChunkPushByteMode (node:internal/streams/readable:512:3)",
    "    at Readable.push (node:internal/streams/readable:392:5)",
    "    at TLSWrap.onStreamRead (node:internal/stream_base_commons:189:23)",
    "    at TLSWrap.callbackTrampoline (node:internal/async_hooks:130:17)"
  ]
}

filter ispresent(errorMessage)
| stats count(*) by errorMessage,bin(1s) as t 
| sort t

filter name = "pg.connect"
| stats count(*) as cnt by ceil(startTimeUnixNano/1000000/1000) as startTimeUnix
| display startTimeUnix, fromMillis(startTimeUnix * 1000) as approximateStartTime,  cnt
| sort startTimeUnix