Answer a question

I have a docker-compose setup with several services, like so:

version: '3.6'

services:

  web:
    build:
      context: ./services/web
      dockerfile: Dockerfile-dev
    volumes:
      - './services/web:/usr/src/app'

    ports:
      - 5001:5000
    environment:
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious
    depends_on:  
      - web-db
      - redis


  web-db:  
    build:
      context: ./services/web/projct/db
      dockerfile: Dockerfile
    ports:
      - 5435:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres


  nginx:
    build:
      context: ./services/nginx
      dockerfile: Dockerfile-dev
    restart: always
    ports:
      - 80:80
    depends_on:
      - web
      - client
      #- redis


  client:
    build:
      context: ./services/client
      dockerfile: Dockerfile-dev
    volumes:
      - './services/client:/usr/src/app'
      - '/usr/src/app/node_modules'
    ports:
      - 3000:3000
    environment:
      - NODE_ENV=development
      - REACT_APP_WEB_SERVICE_URL=${REACT_APP_WEB_SERVICE_URL}
    depends_on:
      - web


  swagger:
    build:
      context: ./services/swagger
      dockerfile: Dockerfile-dev
    volumes:
    - './services/swagger/swagger.json:/usr/share/nginx/html/swagger.json'
    ports:
      - 3008:8080
    environment:
    - URL=swagger.json
    depends_on:
      - web


  scrapyrt:
    image: vimagick/scrapyd:py3
    restart: always
    ports:
      - '9080:9080'
    volumes:
      - ./services/web:/usr/src/app
    working_dir: /usr/src/app/project/api
    entrypoint: /usr/src/app/entrypoint-scrapyrt.sh
    depends_on:
      - web


  redis:
    image: redis:5.0.3-alpine
    restart: always
    expose:
      - '6379'
    ports:
      - '6379:6379'


  monitor:
    image: dev3_web
    ports:
      - 5555:5555
    command:  flower -A celery_worker.celery --port=5555 --broker=redis://redis:6379/0
    depends_on:
      - web
      - redis


  worker-analysis:
    image: dev3_web
    restart: always
    volumes:
      - ./services/web:/usr/src/app
      - ./services/web/celery_logs:/usr/src/app/celery_logs

    command: celery worker -A celery_worker.celery --loglevel=DEBUG --logfile=celery_logs/worker_analysis.log -Q analysis
    environment:
      - CELERY_BROKER=redis://redis:6379/0
      - CELERY_RESULT_BACKEND=redis://redis:6379/0
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious  
    depends_on:
      - web
      - redis
      - web-db
    links:
      - redis:redis
      - web-db:web-db


  worker-scraping:
    image: dev3_web
    restart: always
    volumes:
      - ./services/web:/usr/src/app
      - ./services/web/celery_logs:/usr/src/app/celery_logs

    command: celery worker -A celery_worker.celery --loglevel=DEBUG --logfile=celery_logs/worker_scraping.log -Q scraping
    environment:
      - CELERY_BROKER=redis://redis:6379/0
      - CELERY_RESULT_BACKEND=redis://redis:6379/0
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious  
    depends_on:
      - web
      - redis
      - web-db
    links:
      - redis:redis
      - web-db:web-db


  worker-emailing:
    image: dev3_web
    restart: always
    volumes:
      - ./services/web:/usr/src/app
      - ./services/web/celery_logs:/usr/src/app/celery_logs

    command: celery worker -A celery_worker.celery --loglevel=DEBUG --logfile=celery_logs/worker_emailing.log -Q email
    environment:
      - CELERY_BROKER=redis://redis:6379/0
      - CELERY_RESULT_BACKEND=redis://redis:6379/0
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious
    depends_on:
      - web
      - redis
      - web-db
    links:
      - redis:redis
      - web-db:web-db


  worker-learning:
    image: dev3_web
    restart: always
    volumes:
      - ./services/web:/usr/src/app
      - ./services/web/celery_logs:/usr/src/app/celery_logs

    command: celery worker -A celery_worker.celery --loglevel=DEBUG --logfile=celery_logs/worker_ml.log -Q machine_learning
    environment:
      - CELERY_BROKER=redis://redis:6379/0
      - CELERY_RESULT_BACKEND=redis://redis:6379/0
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious  
    depends_on:
      - web
      - redis
      - web-db
    links:
      - redis:redis
      - web-db:web-db


  worker-periodic:
    image: dev3_web
    restart: always
    volumes:
      - ./services/web:/usr/src/app
      - ./services/web/celery_logs:/usr/src/app/celery_logs

    command: celery beat -A celery_worker.celery --schedule=/tmp/celerybeat-schedule --loglevel=DEBUG --pidfile=/tmp/celerybeat.pid
    environment:
      - CELERY_BROKER=redis://redis:6379/0
      - CELERY_RESULT_BACKEND=redis://redis:6379/0
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@web-db:5432/web_dev 
      - DATABASE_TEST_URL=postgres://postgres:postgres@web-db:5432/web_test
      - SECRET_KEY=my_precious  
    depends_on:
      - web
      - redis
      - web-db
    links:
      - redis:redis
      - web-db:web-db

docker-compose -f docker-compose-dev.yml up -d and docker ps give me:

CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS              PORTS                              NAMES
396d7a1a5443        dev3_nginx             "nginx -g 'daemon of…"   23 hours ago        Up 18 minutes       0.0.0.0:80->80/tcp                 dev3_nginx_1
8ec7a51e2c2a        dev3_web               "celery worker -A ce…"   24 hours ago        Up 19 minutes                                          dev3_worker-analysis_1
e591e6445c64        dev3_web               "celery worker -A ce…"   24 hours ago        Up 19 minutes                                          dev3_worker-learning_1
4d1fd17be3cb        dev3_web               "celery worker -A ce…"   24 hours ago        Up 19 minutes                                          dev3_worker-scraping_1
d25c40060fed        dev3_web               "celery beat -A cele…"   24 hours ago        Up 17 seconds                                          dev3_worker-periodic_1
76df1a600afa        dev3_web               "celery worker -A ce…"   24 hours ago        Up 18 minutes                                          dev3_worker-emailing_1
3442b0ce5d56        vimagick/scrapyd:py3   "/usr/src/app/entryp…"   24 hours ago        Up 20 minutes       6800/tcp, 0.0.0.0:9080->9080/tcp   dev3_scrapyrt_1
81d3ccea4de4        dev3_client            "npm start"              24 hours ago        Up 19 minutes       0.0.0.0:3000->3000/tcp             dev3_client_1
aff5ecf951d2        dev3_web               "flower -A celery_wo…"   24 hours ago        Up 10 seconds       0.0.0.0:5555->5555/tcp             dev3_monitor_1
864f17f39d54        dev3_swagger           "/start.sh"              24 hours ago        Up 19 minutes       80/tcp, 0.0.0.0:3008->8080/tcp     dev3_swagger_1
e69476843236        dev3_web               "/usr/src/app/entryp…"   24 hours ago        Up 19 minutes       0.0.0.0:5001->5000/tcp             dev3_web_1
22fd91b1ab6e        redis:5.0.3-alpine     "docker-entrypoint.s…"   24 hours ago        Up 20 minutes       0.0.0.0:6379->6379/tcp             dev3_redis_1
3a0b2115dd8e        dev3_web-db            "docker-entrypoint.s…"   24 hours ago        Up 19 minutes       0.0.0.0:5435->5432/tcp             dev3_web-db_1

They are all up, but I'm facing exceedingly slow network conditions, with a lot of instability. I have tried to check connectivity between containers and catch some eventual lag, like so:

docker container exec -it e69476843236 ping aff5ecf951d2
PING aff5ecf951d2 (172.18.0.13): 56 data bytes
64 bytes from 172.18.0.13: seq=0 ttl=64 time=0.504 ms
64 bytes from 172.18.0.13: seq=1 ttl=64 time=0.254 ms
64 bytes from 172.18.0.13: seq=2 ttl=64 time=0.191 ms
64 bytes from 172.18.0.13: seq=3 ttl=64 time=0.168 ms

but timing seems alright by these tests, though now and then I get ping: bad address 'aff5ecf951d2' when some service goes down.

Sometimes I get this error:

ERROR: An HTTP request took too long to complete. Retry with --verbose to obtain debug information.
If you encounter this issue regularly because of slow network conditions, consider setting COMPOSE_HTTP_TIMEOUT to a higher value (current value: 60).

And too many times I just have to restart Docker in order to make it work.

How can I docker inspect deeper into slow network conditions and figure out what is wrong? Can newtwork issues be related to volumes?

Answers

The problem manifested itself as the number of containers and the app complexity grew up, (as you always should be aware of).

In my case, I had changed one of the images from Alpine to Slim-Buster (Debian), which is significantly larger.

Turns out I could fix that by simply going to Docker 'Preferences':

clicking on 'Advanced' and increasing memory allocation.

Now it runs smoothly again.