Dowser.Client.HTTP.Profile (Dowser.Client v0.3.0)

Manages the :httpc profiles Dowser.Client.HTTP sends requests through.

A profile is an isolated :httpc manager with its own connection pool, session settings and cookie store. dowser_client never uses :httpc's shared :default profile unless asked to, so its settings — and its keep-alive sessions — are never shared with the rest of the application.

Profiles are started on demand, the first time a request needs one, and configured once with :httpc.set_options/2. Give each cluster its own profile when they should not share a connection pool:

config :dowser_client,
  contexts: [
    default: [endpoint: "https://search.internal:9200", profile: :search],
    logs: [endpoint: "https://logs.internal:9200", profile: :logs]
  ]

Options

:profile_opts (on a context, globally, or per request) is passed to :httpc.set_options/2. dowser_client's defaults, tuned for a search cluster rather than a browser:

max_sessions: 20 — concurrent keep-alive connections per host/port (:httpc's own default is 2, far too few for a search backend).
max_keep_alive_length: 100 — requests queued on one session.
keep_alive_timeout: 120_000 — how long an idle session is kept.
cookies: :disabled — a search API has no use for a cookie store.

Anything :httpc.set_options/2 accepts can be set: :pipeline_timeout, :max_pipeline_length, :proxy, :https_proxy, :ipfamily, :socket_opts, :verbose, :unix_socket, ...

config :dowser_client, profile_opts: [max_sessions: 50, pipeline_timeout: 5_000]

Because options are applied when the profile starts, changing them later has no effect until reset/2 re-applies them.

Summary

Types

t()

Functions

default()

The profile used when none is configured.

default_opts()

The :httpc.set_options/2 defaults applied to every profile.

ensure_started(name, opts \\ [])

Ensures name is started and configured, returning {:ok, name}.

info(name \\ :dowser_client)

Reports :httpc's own view of name — its open sessions, queued requests and current options. Handy for checking that keep-alive is doing what you expect.

invalidate(name)

Forgets that name was started, so the next request starts and configures it again. Does not stop the profile.

reset(name, opts \\ [])

Re-applies opts to name, starting it if needed.