Document the default value of 1 for workers (#940)

docs/deployment.md

@@ -45,7 +45,7 @@ Options:
 
   --workers INTEGER               Number of worker processes. Defaults to the
                                   $WEB_CONCURRENCY environment variable if
-                                  available. Not valid with --reload.
+                                  available, or 1. Not valid with --reload.
 
   --loop [auto|asyncio|uvloop]    Event loop implementation.  [default: auto]
   --http [auto|h11|httptools]     HTTP protocol implementation.  [default:

docs/index.md

@@ -115,7 +115,7 @@ Options:
 
   --workers INTEGER               Number of worker processes. Defaults to the
                                   $WEB_CONCURRENCY environment variable if
-                                  available. Not valid with --reload.
+                                  available, or 1. Not valid with --reload.
 
   --loop [auto|asyncio|uvloop]    Event loop implementation.  [default: auto]
   --http [auto|h11|httptools]     HTTP protocol implementation.  [default:

docs/settings.md

@@ -24,7 +24,7 @@ equivalent keyword arguments, eg. `uvicorn.run("example:app", port=5000, reload=
 
 ## Production
 
-* `--workers <int>` - Use multiple worker processes. Defaults to the value of the `$WEB_CONCURRENCY` environment variable.
+* `--workers <int>` - Use multiple worker processes. Defaults to the `$WEB_CONCURRENCY` environment variable if available, or 1.
 
 ## Logging
 

uvicorn/main.py

@@ -90,7 +90,7 @@ def print_version(ctx, param, value):
     default=None,
     type=int,
     help="Number of worker processes. Defaults to the $WEB_CONCURRENCY environment"
-    " variable if available. Not valid with --reload.",
+    " variable if available, or 1. Not valid with --reload.",
 )
 @click.option(
     "--loop",