Server

class Server(object)

Server runs an HTTP server started in an @modal.enter method.

See the guide for more information.

Generally, you will not construct a Server directly. Instead, use the @app.server() decorator.

@app.server(port=8080, routing_region="us-east")
class MyServer:
    @modal.enter()
    def start_server(self):
        self.process = subprocess.Popen(["python3", "-m", "http.server", "8080"])

object_id

object_id(self)

Modal’s internal ID for this Server instance.

logs

logs: ServerLogsManager

Access logs for a Server.

Use fetch() to read logs from a UTC time range, tail() to read the most recent logs, and stream() to follow new logs as they arrive.

See Also

modal app logs: CLI access to logs for an App.

logs.fetch

fetch(self, *, since, until=None, source=None, search_text="")

Fetch Server logs corresponding to the date range and filters.

Parameters

since datetime

Start date to fetch logs from. Must be in UTC or timezone-naive, which is interpreted as local time.

until datetime | None

Defaults to current date if None. Must be in UTC or timezone-naive, which is interpreted as local time.

source LogSource | None

Filter by source: 'stdout', 'stderr', or 'system'.

search_text str

Filter by search text. (Default is "")

Yields

LogEntry objects in chronological order.

Usage

server = modal.Server.from_name("my-app", "web")

for entry in server.logs.fetch(
    since=datetime.now() - timedelta(minutes=25),
    source="stdout",
):
    print(entry.message, end="")

logs.tail

tail(self, entries=100, *, source=None)

Fetch the most recent Server logs.

Parameters

entries int

The number of log entries to return. (Default is 100)

source LogSource | None

Filter by source: 'stdout', 'stderr', or 'system'.

Yields

LogEntry objects in chronological order.

Usage

server = modal.Server.from_name("my-app", "web")

for entry in server.logs.tail(20):
    print(entry.message, end="")

logs.stream

stream(self, timeout=None)

Stream new Server logs until the timeout is reached.

Parameters

timeout float | None

Number of seconds to wait between log entries before terminating the stream. By default, this will block until it is interrupted.

Yields

LogEntry objects as they arrive.

Usage

server = modal.Server.from_name("my-app", "web")

for entry in server.logs.stream(timeout=60):
    print(entry.message, end="")

get_url

get_url(self)

The URL for making requests to this Server.

update_autoscaler

update_autoscaler(self, *, target_concurrency=None, min_containers=None,
    max_containers=None, buffer_containers=None, scaleup_window=None,
    scaledown_window=None)

Override the current autoscaler behavior for this Server.

Unspecified parameters will retain their current value, i.e. either the static value from the @app.server() decorator, or an override value from a previous call to this method.

Subsequent deployments of the App containing this Server will reset the autoscaler back to its static configuration.

Parameters

target_concurrency int | None

Target number of concurrent requests per container.

min_containers int | None

Minimum number of containers to keep running regardless of demand.

max_containers int | None

Limit on the number of containers that can be concurrently running.

buffer_containers int | None

Extra containers to scale up beyond current demand.

scaleup_window int | None

Seconds of sustained demand required before scaling up new containers.

scaledown_window int | None

Maximum duration (in seconds) idle containers wait before scaling down.

Usage

server = modal.Server.from_name("my-app", "Server")

# Always have at least 2 containers running, with an extra buffer of 2 containers
server.update_autoscaler(min_containers=2, buffer_containers=1)

# Limit this Server to avoid spinning up more than 5 containers
server.update_autoscaler(max_containers=5)

# Require 30 seconds of sustained demand before scaling up
server.update_autoscaler(scaleup_window=30)

# Adjust Server autoscaling to target 20 concurrent requests per replica
server.update_autoscaler(target_concurrency=20)

# Disable the Server autoscaling by setting target_concurrency to 0
server.update_autoscaler(target_concurrency=0)

hydrate

hydrate(self, client=None)

Synchronize the local object with its identity on the Modal server.

It is rarely necessary to call this method explicitly, as most operations will lazily hydrate when needed. The main use case is when you need to access object metadata, such as its ID.

from_name

from_name(cls, app_name, name, *, environment_name=None, client=None)

Reference a Server from a deployed App by its name.

This is a lazy method that defers hydrating the local object with metadata from Modal servers until the first time it is actually used.