Using gunicorn to run upto 4 workers. This should fix the problems of the whole program crashing.

.env

@@ -6,6 +6,8 @@ SQLALCHEMY_DATABASE_URI=postgresql://postgres:123456@localhost:5432/petty
 MODULE_NAME=barker.main
 PROJECT_NAME=barker
 
+MAX_WORKERS=4
+
 REDIS_HOST=localhost
 REDIS_PORT=6379
 

barker/gunicorn.conf.py

@@ -0,0 +1,68 @@
+import json
+import multiprocessing
+import os
+
+
+workers_per_core_str = os.getenv("WORKERS_PER_CORE", "1")
+max_workers_str = os.getenv("MAX_WORKERS")
+use_max_workers = None
+if max_workers_str:
+    use_max_workers = int(max_workers_str)
+web_concurrency_str = os.getenv("WEB_CONCURRENCY", None)
+
+host = os.getenv("HOST", "0.0.0.0")
+port = os.getenv("PORT", "9995")
+bind_env = os.getenv("BIND", None)
+use_loglevel = os.getenv("LOG_LEVEL", "info")
+if bind_env:
+    use_bind = bind_env
+else:
+    use_bind = f"{host}:{port}"
+
+cores = multiprocessing.cpu_count()
+workers_per_core = float(workers_per_core_str)
+default_web_concurrency = workers_per_core * cores
+if web_concurrency_str:
+    web_concurrency = int(web_concurrency_str)
+    assert web_concurrency > 0
+else:
+    web_concurrency = max(int(default_web_concurrency), 2)
+    if use_max_workers:
+        web_concurrency = min(web_concurrency, use_max_workers)
+accesslog_var = os.getenv("ACCESS_LOG", "-")
+use_accesslog = accesslog_var or None
+errorlog_var = os.getenv("ERROR_LOG", "-")
+use_errorlog = errorlog_var or None
+graceful_timeout_str = os.getenv("GRACEFUL_TIMEOUT", "120")
+timeout_str = os.getenv("TIMEOUT", "120")
+keepalive_str = os.getenv("KEEP_ALIVE", "5")
+
+# Gunicorn config variables
+loglevel = use_loglevel
+workers = web_concurrency
+bind = use_bind
+errorlog = use_errorlog
+worker_tmp_dir = "/dev/shm"
+accesslog = use_accesslog
+graceful_timeout = int(graceful_timeout_str)
+timeout = int(timeout_str)
+keepalive = int(keepalive_str)
+
+
+# For debugging and testing
+log_data = {
+    "loglevel": loglevel,
+    "workers": workers,
+    "bind": bind,
+    "graceful_timeout": graceful_timeout,
+    "timeout": timeout,
+    "keepalive": keepalive,
+    "errorlog": errorlog,
+    "accesslog": accesslog,
+    # Additional, non-gunicorn variables
+    "workers_per_core": workers_per_core,
+    "use_max_workers": use_max_workers,
+    "host": host,
+    "port": port,
+}
+print(json.dumps(log_data))

barker/logging.conf

@@ -0,0 +1,53 @@
+[loggers]
+keys=root, gunicorn.error, gunicorn.access
+
+[handlers]
+keys=console, error, access
+
+[formatters]
+keys=generic, error, access
+
+[logger_root]
+level=INFO
+handlers=console
+qualname=root
+
+[logger_gunicorn.error]
+level=INFO
+handlers=console
+qualname=gunicorn.error
+
+[logger_gunicorn.access]
+level=INFO
+handlers=access
+qualname=gunicorn.access
+
+[handler_console]
+class=StreamHandler
+formatter=generic
+args=(sys.stdout, )
+
+[handler_error]
+class=StreamHandler
+formatter=error
+args=(sys.stdout, )
+
+[handler_access]
+class=StreamHandler
+formatter=access
+args=(sys.stdout, )
+
+[formatter_generic]
+format=%(asctime)s [%(name)s %(levelname)s] %(message)s
+datefmt=%Y-%m-%d %H:%M:%S %Z
+class=logging.Formatter
+
+[formatter_error]
+format=%(asctime)s [%(name)s %(levelname)s] %(message)s | %(funcName)s() | %(pathname)s L%(lineno)-4d
+datefmt=%Y-%m-%d %H:%M:%S %Z
+class=logging.Formatter
+
+[formatter_access]
+format=%(asctime)s [%(name)s %(levelname)s] %(message)s
+datefmt=%Y-%m-%d %H:%M:%S %Z
+class=logging.Formatter

barker/pyproject.toml

@@ -22,6 +22,7 @@ starlette = "^0.17.1"
 arq = "^0.22"
 aiohttp = "^3.8.1"
 cryptography = "^36.0.2"
+gunicorn = "^20.1.0"
 
 [tool.poetry.dev-dependencies]
 flake8 = "^4.0.1"

docker/app/Dockerfile

@@ -50,4 +50,4 @@ RUN chmod 777 /app/docker-entrypoint.sh \
     && ln -s /app/docker-entrypoint.sh /
 ENTRYPOINT ["docker-entrypoint.sh"]
 
-CMD ["poetry", "run", "python", "-m", "barker"]
+CMD ["poetry", "run", "gunicorn", "app.main:app", "--worker-class", "uvicorn.workers.UvicornWorker", "--config", "/app/gunicorn.conf.py", "--log-config", "/app/logging.conf"]