docs: remove mentions of logical replication change streaming

docs/api/service.md

@@ -16,7 +16,6 @@ Configuration options are passed as environment variables, e.g.:
 ```shell
 docker run \
     -e "DATABASE_URL=postgresql://..." \
-    -e "LOGICAL_PUBLISHER_HOST=..." \
     -e "PG_PROXY_PASSWORD=..." \
     -e "AUTH_JWT_ALG=HS512" \
     -e "AUTH_JWT_KEY=..." \
@@ -132,88 +131,6 @@ Configure how Electric connects to Postgres and exposes its HTTP/WebSocket API.
   <LogLevel />
 </EnvVarConfig>
 
-## Write-to-PG mode
-
-Electric writes data to Postgres using one of two modes:
-
-1. [logical replication](#logical-replication-mode)
-2. [direct writes](#direct-writes-mode)
-
-:::caution
-The mode you choose affects your networking config and [database user permissions](#database-user-permissions).
-:::
-
-import ElectricWriteToPgMode from './_ELECTRIC_WRITE_TO_PG_MODE.md'
-
-#### ELECTRIC_WRITE_TO_PG_MODE
-
-<EnvVarConfig
-    name="ELECTRIC_WRITE_TO_PG_MODE"
-    defaultValue="logical_replication"
-    example="direct_writes">
-  <ElectricWriteToPgMode />
-</EnvVarConfig>
-
-### Logical replication mode
-
-In `logical_replication` mode, Electric exposes a logical replication publisher service over TCP that speaks the [Logical Streaming Replication Protocol](https://www.postgresql.org/docs/current/protocol-logical-replication.html).
-
-Postgres connects to Electric on `LOGICAL_PUBLISHER_HOST:LOGICAL_PUBLISHER_PORT` and establishes a logical replication subscription to this publisher service. Writes are then streamed in and applied using the logical replication subscription.
-
-```
-         | <----------- DATABASE_URL ----------- |
-Postgres |                                       | Electric
-         | ---- LOGICAL_PUBLISHER_HOST:PORT ---> |
-```
-
-:::caution Caution
-In logical replication mode:
-
-1. the [database user](#database-user-permissions) that Electric connects to Postgres as must have the [`SUPERUSER` role attribute](https://www.postgresql.org/docs/16/role-attributes.html#ROLE-ATTRIBUTES)
-2. Postgres must be able to connect to Electric (i.e.: must be able to establish an outbound TCP connection) on the host and port that you configure
-
-As a result, you must make sure (in terms of networking / firewalls) not only that Postgres is reachable from Electric but also that Electric is reachable from Postgres. And Electric must know its own address, in order to provide it to Postgres when setting up the logical replication publication that allows writes to be replicated into Postgres.
-:::
-
-import LogicalPublisherHost from './_LOGICAL_PUBLISHER_HOST.md'
-import LogicalPublisherPort from './_LOGICAL_PUBLISHER_PORT.md'
-
-#### LOGICAL_PUBLISHER_HOST
-
-<EnvVarConfig
-    name="LOGICAL_PUBLISHER_HOST"
-    required={true}
-    example="example.com">
-  <LogicalPublisherHost />
-</EnvVarConfig>
-
-#### LOGICAL_PUBLISHER_PORT
-
-<EnvVarConfig
-    name="LOGICAL_PUBLISHER_PORT"
-    defaultValue="5433"
-    example="65433">
-  <LogicalPublisherPort />
-</EnvVarConfig>
-
-### Direct writes mode
-
-In `direct_writes` mode, Electric writes data to Postgres using a standard interactive client connection. This avoids the need for Postgres to be able to connect to Electric and reduces the permissions required for the database user that Electric connects to Postgres as.
-
-```
-Postgres | <----------- DATABASE_URL ----------- | Electric
-```
-
-No additional configuration is required for direct writes mode. The `LOGICAL_PUBLISHER_HOST` and `LOGICAL_PUBLISHER_PORT` variables are not required and are ignored.
-
-:::info Why are there two modes?
-Originally (prior to v0.8) all writes to Postgres were made using logical replication.
-
-In [version 0.8](/blog/2023/12/13/electricsql-v0.8-released#from-superuser-to-supabase), Electric added direct writes mode to reduce the database user permissions required and increase compatibility with Postgres hosting providers.
-
-In future, we may deprecate logical replication and consolidate on direct writes. However, logical replication may have performance advantages and, for now, we've kept both modes available while direct writes mode gains maturity and we learn more about the operational characteristics of both modes.
-:::
-
 ## Database user permissions
 
 The Electric sync service connects to Postgres using the [`DATABASE_URL`](#database_url) connection string, in the format `postgresql://[userspec@][hostspec][/dbname]`.

docs/deployment/_render.md

@@ -51,16 +51,6 @@ services:
       value: "..."
     - key: DATABASE_URL
       value: "postgresql://..."
-    - key: LOGICAL_PUBLISHER_HOST
-      fromService:
-        type: web
-        name: tcp-proxy
-        property: host
-    - key: LOGICAL_PUBLISHER_PORT
-      fromService:
-        type: web
-        name: tcp-proxy
-        property: port
 - type: web
   name: http-proxy
   runtime: image

docs/deployment/concepts.md

@@ -65,18 +65,11 @@ Electric connects to Postgres using a `DATABASE_URL` connection string. In addit
 
 Electric actually connects to Postgres in three ways:
 
-1. it uses a normal interactive client connection to bootstrap resources and make database queries (for example, when you subscribe to a [Shape](../usage/data-access/shapes.md), Electric uses the interactive connection to query for all the rows in the shape)
-2. it establishes a logical replication subscription to consume changes from Postgres
+1. it uses a normal interactive client connection to bootstrap resources and make database queries (for example, when you subscribe to a [Shape](../usage/data-access/shapes.md), Electric uses the interactive connection to query for all the rows in the shape),
+2. it establishes a logical replication subscription to consume changes from Postgres,
 3. it writes changes to Postgres that it receives from clients over the [Satellite replication protocol](../api/satellite.md)
 
-This last one, writes changes to Postgres, can be done in two ways:
-
-- you can set `ELECTRIC_WRITE_TO_PG_MODE=direct_writes` to write data to Postgres using a normal interactive client connection
-- you can set `ELECTRIC_WRITE_TO_PG_MODE=logical_replication` to stream data into Postgres using a logical replication publication
-
-Direct writes mode works out of the box and is the easiest mode to configure, with no additional network connectivity required. Logical replication mode requires exposing a TCP host and port to Postgres, so that Postgres can establish a logical replication subscription. This can be configured using the `LOGICAL_PUBLISHER_HOST` and `LOGICAL_PUBLISHER_PORT` env vars.
-
-See <DocPageLink path="api/service" /> for more information.
+Writes are made over a regular connection with some additional configuration to distinguish client writes and direct-to-postgres writes in conflict resolution. See <DocPageLink path="api/service" /> for more information.
 
 ### 2. Migrations <-> Proxy
 

docs/deployment/digital-ocean.md

@@ -225,7 +225,6 @@ services:
       DATABASE_URL: "postgresql://postgres:******@example.com/postgres"
       PG_PROXY_PASSWORD: "******"
       AUTH_MODE: "insecure"
-      ELECTRIC_WRITE_TO_PG_MODE: "direct_writes"
     ports:
       - 80:5133
       - 65432:65432

docs/deployment/docker.md

@@ -12,7 +12,6 @@ See <DocPageLink path="usage/installation/service" /> to get familiar with confi
 ```shell
 docker run \
     -e "DATABASE_URL=postgresql://..." \
-    -e "LOGICAL_PUBLISHER_HOST=..." \
     -e "PG_PROXY_PASSWORD=..." \
     -e "AUTH_JWT_ALG=HS512" \
     -e "AUTH_JWT_KEY=..." \

docs/deployment/fly.md

@@ -33,7 +33,6 @@ app = "electric-on-fly-test-app"
 [env]
   AUTH_MODE = "insecure"
   DATABASE_URL = "postgresql://..."
-  ELECTRIC_WRITE_TO_PG_MODE = "direct_writes"
   PG_PROXY_PASSWORD = "proxy_password"
 
 # The main Internet-facing service of Electric

docs/deployment/k8s.md

@@ -35,8 +35,6 @@ spec:
         env:
         - name: DATABASE_URL
           value: "postgresql://..."
-        - name: LOGICAL_PUBLISHER_HOST
-          value: "..."
         - name: PG_PROXY_PASSWORD
           value: "..."
         - name: AUTH_JWT_ALG
@@ -46,8 +44,6 @@ spec:
         ports:
         - name: satellite-http
           containerPort: 5133
-        - name: logical-pub-tcp
-          containerPort: 5433
         - name: pg-proxy-tcp
           containerPort: 65432
 ```

docs/deployment/supabase.md

@@ -84,7 +84,6 @@ Run your [Electric sync service](../api/service), either locally or [via one of
 - set `AUTH_JWT_KEY` to the "JWT Secret" value you retrieved in step 3 above
 - set `DATABASE_URL` to the connection string you retrieved in step 2 above
 - set `DATABASE_USE_IPV6` to `true` unless you've purchased the IPv4 add-on for Supabase
-- set `ELECTRIC_WRITE_TO_PG_MODE` to `direct_writes`
 - set `PG_PROXY_PASSWORD` to a secure password value and note it down
 
 Depending on how you run Electric these could be passed as arguments to Docker, set in a ENV file or entered into a managed host's dashboard. For example, to run Electric locally using Docker (replacing the `...` placeholder values with your specific values):
@@ -95,7 +94,6 @@ docker run \
     -e "AUTH_JWT_KEY=..." \
     -e "DATABASE_URL=..." \
     -e "DATABASE_USE_IPV6=true" \
-    -e "ELECTRIC_WRITE_TO_PG_MODE=direct_writes" \
     -e "PG_PROXY_PASSWORD=..." \
     -e "PG_PROXY_PORT=65432" \
     -p 5133:5133 \

docs/examples/notes/running.md

@@ -47,14 +47,10 @@ npm run dev
 
 ### Connecting Electric to Postgres
 
-The Electric sync service connects to Postgres using the `DATABASE_URL` environment variable. Depending on your choice of write mode, Postgres may also need to connect to Electric to consume a logical replication publication.
-
-This is configured using the `LOGICAL_PUBLISHER_HOST` (and `LOGICAL_PUBLISHER_PORT`) environment variables:
+The Electric sync service connects to Postgres using the `DATABASE_URL` environment variable. Postgres is configured to use `logical` replication to stream changes to Electric.
 
 ```
-         |<--------DATABASE_URL----------|
-Postgres |                               | Electric
-         |-----LOGICAL_PUBLISHER_HOST--->|
+Postgres |<--------DATABASE_URL----------| Electric
 ```
 
 See <DocPageLink path="api/service" /> for more information.

docs/quickstart/_setup_manual.md

@@ -23,7 +23,6 @@ docker pull electricsql/electric:latest
 docker run \
     -e "DATABASE_URL=postgresql://..." \
     -e "DATABASE_REQUIRE_SSL=false \
-    -e "LOGICAL_PUBLISHER_HOST=..." \
     -e "PG_PROXY_PASSWORD=..." \
     -e "AUTH_MODE=insecure" \
     -p 5133:5133 \

docs/reference/architecture.md

@@ -95,11 +95,7 @@ Whilst local writes are final, they are still subject to concurrent merge semant
 
 ### Streaming into Electric
 
-When the local database migrations are generated from the Postgres DDL changes, triggers are added that automatically copy insert, update and delete operations on the tables to the "oplog" table. The satellite process then processes these operations by sending them to the Electric server over the Satellite protocol. Electric then applies server-side validation and authorisation before sending on to Postgres over the incoming logical-replication stream.
-
-:::note
-Electric acts as a [logical replication publisher](https://www.postgresql.org/docs/current/logical-replication.html). This is why you configure a `LOGICAL_PUBLISHER_HOST` when deploying the Electric sync service -- so that Postgres can connect to consume inbound logical replication.
-:::
+When the local database migrations are generated from the Postgres DDL changes, triggers are added that automatically copy insert, update and delete operations on the tables to the "oplog" table. The satellite process then processes these operations by sending them to the Electric server over the Satellite protocol. Electric then applies server-side validation and authorisation before executing the writes on Postgres.
 
 ### Streaming into Postgres
 

docs/usage/installation/service.md

@@ -11,15 +11,13 @@ You can run the [pre-packaged Docker images](#images) published on Docker Hub, o
 
 ## Configuration
 
-The Electric sync service is configured using environment variables. The three required variables are:
+The Electric sync service is configured using environment variables. The two required variables are:
 
 - `DATABASE_URL` in the format of a Postgres [Connection URI](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING-URIS)
-- `LOGICAL_PUBLISHER_HOST` that the sync service is running on (must be accessible from the Postgres instance to establish an inbound replication subscription)
 - `PG_PROXY_PASSWORD` to safe-guard access to the [Migrations proxy](../data-modelling/migrations.md#migrations-proxy)
 
 ```shell
 DATABASE_URL="postgresql://user:password@localhost:5432/electric"
-LOGICAL_PUBLISHER_HOST="localhost"
 PG_PROXY_PASSWORD="..."
 ```
 
@@ -34,7 +32,6 @@ Pre-packaged images are available on Docker Hub at [electricsql/electric](https:
 ```shell
 docker run \
     -e "DATABASE_URL=postgresql://..." \
-    -e "LOGICAL_PUBLISHER_HOST=..." \
     -e "PG_PROXY_PASSWORD=..." \
     -e "AUTH_MODE=insecure" \
     -p 5133:5133 \
@@ -75,7 +72,6 @@ services:
     environment:
       DATABASE_URL: postgresql://postgres:pg_password@pg/postgres
       DATABASE_REQUIRE_SSL: false
-      LOGICAL_PUBLISHER_HOST: electric
       PG_PROXY_PASSWORD: proxy_password
       AUTH_MODE: insecure
     ports:
@@ -103,7 +99,6 @@ Then run:
 ```shell
 docker run \
     -e "DATABASE_URL=postgresql://..." \
-    -e "LOGICAL_PUBLISHER_HOST=..." \
     -e "PG_PROXY_PASSWORD=..." \
     -e "AUTH_MODE=insecure" \
     -p 5133:5133 \

examples/checkout/electric/docker-compose.yml

@@ -12,7 +12,6 @@ services:
     environment:
       DATABASE_URL: postgresql://postgres:[email protected]:5432/postgres
       PG_PROXY_PASSWORD: proxy_password
-      ELECTRIC_WRITE_TO_PG_MODE: direct_writes
       AUTH_MODE: secure
       AUTH_JWT_ALG: HS256
       AUTH_JWT_KEY: XXXXXXXXXXX

examples/recipes/backend/docker-compose.yaml

@@ -36,7 +36,6 @@ services:
     environment:
       DATABASE_URL: postgresql://postgres:pg_password@postgres:${PG_PORT:-5432}/${APP_NAME:-electric}
       PG_PROXY_PASSWORD: proxy_password
-      LOGICAL_PUBLISHER_HOST: electric
       AUTH_MODE: insecure
     ports:
       - ${ELECTRIC_PORT:-5133}:5133