Upgrading a host from 0.6 to 0.11

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This page says what a host changes to move statifier_router from 0.6.0 to 0.11.2, one minor at a time: 0.6 to 0.7, 0.7 to 0.8, 0.8 to 0.9, 0.9 to 0.10 and 0.10 to 0.11. A host here is the code that embeds the package: the StatifierRouter.Config it builds, the migrations it runs, the bindings it routes with, the reapers it schedules, and any front, wrapper or send processor of its own. What each release added is in the changelog; this page lists only what a host has to do about it, and says NONE where the answer is nothing.

Take the minors in order, and move the pin with each one, as the README's Compatibility section recommends: {:statifier_router, "~> 0.7.0"}, then "~> 0.8.0", then "~> 0.9.0", then "~> 0.10.0", then "~> 0.11.0". A patch release rides its minor's pin, so each section below covers the patches of the minor it moves to. The statifier requirement is ~> 2.9 through 0.8 and ~> 2.10 from 0.9 on; the statifier_persistence requirement stays ~> 0.18 on every step.

A host on 0.6.0 has run migration versions V01 and V02. One release in this range adds a version to the walk, 0.8.0 (V03), and one adds a table outside it, 0.9.0 (V04, opt-in); the last two sections of this page give both migrations in full.

0.6 to 0.7

Must change: NONE, unless one of these is you.

  • If you set :bindings_resolver and read the :unchecked entries of StatifierRouter.Contracts.check/3, skip or match the entry the list now opens with, %{reason: :bindings_resolver, location: nil}, before you read location: it is the one entry with no location. Keep checking each scope's bindings with StatifierRouter.Contracts.undeclared_binding_events/2. A configuration without a resolver gets the report it got before. This is the release's one Breaking entry.
  • If you match StatifierRouter.Config.new/1's refusals exhaustively, add {:exclusive_keys, :send_handlers, :send_types}. It is answered only to a configuration that gives a non-empty :send_handlers beside a :persistence_options carrying its own :send_types and no :send_type.

May start doing:

  • If you set :send_type and serve send types of your own, declare them in :send_handlers, a map from each type string to its processor module. Before 0.7 such a configuration had nowhere to put them: a :send_types of your own beside :send_type is refused with {:declared_send_types, send_type}, so StatifierRouter.Contracts.check/3 reported your types under :unsupported_types. Declared in :send_handlers, they join the router's type in the one snapshot every delivery carries, and check/3 stops reporting them. A configuration without :send_type that passes its own :send_types in :persistence_options keeps working as it is. How to fit the router into an engine of your own, "Step 4. Declare the send types the host serves", shows the option.

0.7 to 0.8

  • Add the V03 migration. A host that has already run V02 adds one migration calling StatifierRouter.Migrations.up(from: 3), with down(from: 3, version: 3) on rollback, passing the same options its first router migration passes: :table_prefix and :prefix name the table, and the layout options (:leading_columns, :timestamps_position, :column_collations) change nothing, since V03 creates no table. V03: the subscription index name below gives the migration in full. A first migration that calls up/1 with no version: runs V03 on a fresh database too; one capped at version: 2 does not, and the index keeps V02's name until the new migration runs.
  • If you match the subscription index's name as a unique violation's constraint (an Ecto.ConstraintError, or a unique_constraint/3 naming it), match <table>_invocation_index once V03 has run, where <table> is the subscription table's name under your :table_prefix.
  • If you set a :table_prefix of your own, the name you read back before V03 depends on it. V02 named the index after the subscription table plus 40 bytes, so a prefix of 10 bytes or fewer kept it inside the 63 bytes Postgres keeps of an identifier, while the default prefix, "statifier_router_", took it to 70 and Postgres created it truncated. V03 finds the index under the name Postgres gave it either way, and renames it. StatifierRouter.Migrations, "Index names and a long :table_prefix", says what a long prefix does to the other index names.
  • If you run on SQLite, do not stop at 0.8: V03's ALTER INDEX fails a SQLite migration on 0.8.0, and StatifierRouter.Addresses.reap/3 fails any SQLite reap that finds a row to write. Take 0.9.2, which fixes both (see the next section).

May start doing:

0.8 to 0.9

  • Move statifier to 2.10 or later first. 0.9.0 requires {:statifier, "~> 2.10"}, whether or not you set :basichttp.
  • NONE else for a host that does not set :basichttp. No version is added to the walk, and StatifierRouter.Migrations.up/1 and down/1 behave as before.
  • If you run on SQLite, take 0.9.2: on 0.9.1 V03 does nothing on SQLite, and on 0.9.2 StatifierRouter.Addresses.reap/3 runs on SQLite, writing more than 500 rows in batches of 500, one statement each. A Postgres host sees the same counts.

May start doing:

  • If you want an execution to take events at an HTTP location of its own, set :basichttp and add the opt-in location table's migration (The opt-in location table below). On such a configuration a binding whose id is basichttp is refused as {:reserved_binding_id, "basichttp"}, so rename one first if you have it. How to give an execution an HTTP location walks the rest.

0.9 to 0.10

Must change: NONE.

  • If you set :basichttp and keep a repo's query log at :debug, the location token no longer appears in the router's own Ecto query log, but it is still carried by the repo's query telemetry event and by the execution's persisted state: never run a production repo at :debug.
  • If you schedule StatifierRouter.Addresses.reap/3, nothing changes: on Postgres each batch is one array statement again, with the same counts. Check while you are there that your sweep pages through the table: one call examines at most :limit rows (1000 by default) and answers a next cursor, and a sweep calls again with after: next until next is nil. A host that never passes after: examines the first :limit rows each time and frees nothing behind them (StatifierRouter.Addresses, "Its cost is bounded"; How to fit the router's tables to a host, "Step 1. Schedule the reapers").

May start doing:

  • If your create and step calls need a context of your own around them (a tenancy, or a value your hooks read from the process), set :around_delivery on StatifierRouter.Config, a module exporting around_delivery/3 or an arity-3 fun handed (scope, door, work), that calls work exactly once and answers what it answered. How to fit the router into an engine of your own, "Step 2. Wrap a whole delivery", lists the doors.

0.10 to 0.11

Must change: NONE. 0.11.1 and 0.11.2 change no code: 0.11.2 moves the README's long sections to pages of their own, this one among them.

  • If your repo's adapter module wraps Ecto.Adapters.SQLite3, take 0.11.0 or later before you run V03: from 0.11.0 V03 does nothing on such a repo, as on the stock SQLite adapter, where before it sent an ALTER INDEX SQLite cannot parse. A Postgres repo, wrapped or not, is renamed as before.

May start doing:

  • If you set :around_delivery and want a send's delivery to the execution target wrapped too, set wrap_target: true beside it. Your wrapper is then also handed the door :target, so a wrapper that matches its doors exhaustively adds a clause for it.
  • If your own job delivers an event back in through StatifierRouter.Delivery.deliver_event/4 and the step it drives reaches a route a scope in :route_overrides overrides, set run_in_scope: true in the envelope. Without it the route is refused as {:no_delivery_scope, name}, as before. Any value other than a boolean raises ArgumentError before anything is written. How to give an execution an HTTP location, "Step 4. Send from a durable execution", shows the envelope.

V03: the subscription index name

V03 renames the subscription table's unique index, which V02 named past the 63 bytes Postgres keeps of an identifier, so Postgres created it under a truncated name. A host that has already run V02 adds:

defmodule MyApp.Repo.Migrations.RenameStatifierRouterSubscriptionIndex do
  use Ecto.Migration

  def up, do: StatifierRouter.Migrations.up(from: 3)
  def down, do: StatifierRouter.Migrations.down(from: 3, version: 3)
end

with the same :table_prefix and :prefix its earlier migrations pass. Nothing is rebuilt, and on a database where the index already carries its new name the migration does nothing. A first migration that calls up/1 with no version:, as the README's Installation does, runs every version this package knows, so on a fresh database it runs V03 too; the migration above is still needed for every database that ran the first one before V03 existed, and on a fresh one it finds the index already renamed. StatifierRouter.Migrations says what a long :table_prefix does to the index names.

The opt-in location table

V04, the location table a configuration with :basichttp keeps its tokens in (see How to give an execution an HTTP location), is opt-in (ADR-0002, the Amendment of 2026-09-30 "the location table is opt-in, outside the version walk"): it is not in the version walk, so up/1 and down/1, capped or not, never create, drop or require it, and every migration above behaves exactly as it did before V04 existed. A host that does not set the key needs nothing. One that does adds a migration of its own after the ones it has:

defmodule MyApp.Repo.Migrations.AddStatifierRouterLocations do
  use Ecto.Migration

  def up, do: StatifierRouter.Migrations.up_locations()
  def down, do: StatifierRouter.Migrations.down_locations()
end

with the same :table_prefix, :prefix, layout options and :primary_key its earlier migrations pass; the two calls take no :from or :version. up_locations/1 creates only what is missing and down_locations/1 drops the table only if it is there. The table references the address table, so it has to go before V01's tables do: as a later migration, this one is rolled back first, which is the order Ecto's rollback takes.