From 9d3d538a2d054e78fdf4c655ff660bc31de02ed9 Mon Sep 17 00:00:00 2001 From: Slavi Pantaleev Date: Tue, 21 Jan 2020 00:12:49 +0200 Subject: [PATCH] Use C collation for Postgres to appease Synapse --- CHANGELOG.md | 17 +++++++++++++++++ .../matrix-postgres/tasks/upgrade_postgres.yml | 7 ++++++- .../templates/env-postgres-server.j2 | 5 ++++- 3 files changed, 27 insertions(+), 2 deletions(-) diff --git a/CHANGELOG.md b/CHANGELOG.md index d5596724..620d8ec3 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,3 +1,20 @@ +# 2020-01-21 + +## Postgres collation changes (action required!) + +By default, we've been using a UTF-8 collation for Postgres. This is known to cause Synapse some troubles (see the [relevant issue](https://github.com/matrix-org/synapse/issues/6722)) on systems that use [glibc](https://www.gnu.org/software/libc/). We run Postgres in an [Alpine Linux](https://alpinelinux.org/) container (which uses [musl](https://www.musl-libc.org/), and not glibc), so our users are likely not affected by the index corruption problem observed by others. + +Still, we might become affected in the future. In any case, it's imminent that Synapse will complain about databases which do not use a C collation. + +To avoid future problems, we recommend that you run the following command: + +``` +ansible-playbook -i inventory/hosts setup.yml --tags=upgrade-postgres --extra-vars='{"postgres_force_upgrade": true}' +``` + +It forces a [Postgres database upgrade](docs/maintenance-postgres.md#upgrading-postgresql), which would recreate your Postgres database using the proper (`C`) collation. If you are low on disk space, or run into trouble, refer to the Postgres database upgrade documentation page. + + # 2020-01-14 ## Added support for Appservice Webhooks diff --git a/roles/matrix-postgres/tasks/upgrade_postgres.yml b/roles/matrix-postgres/tasks/upgrade_postgres.yml index 9a30e819..8a3886b3 100644 --- a/roles/matrix-postgres/tasks/upgrade_postgres.yml +++ b/roles/matrix-postgres/tasks/upgrade_postgres.yml @@ -20,6 +20,11 @@ postgres_start_wait_time: 15 when: "postgres_start_wait_time|default('') == ''" +- name: Set postgres_force_upgrade, if not provided + set_fact: + postgres_force_upgrade: false + when: "postgres_force_upgrade|default('') == ''" + - name: Fail, if trying to upgrade external Postgres database fail: msg: "Your configuration indicates that you're not using Postgres from this role. There is nothing to upgrade." @@ -45,7 +50,7 @@ - name: Abort, if already at latest Postgres version fail: msg: "You are already running the latest Postgres version supported ({{ matrix_postgres_docker_image_latest }}). Nothing to do" - when: "matrix_postgres_detected_version_corresponding_docker_image == matrix_postgres_docker_image_latest" + when: "matrix_postgres_detected_version_corresponding_docker_image == matrix_postgres_docker_image_latest and not postgres_force_upgrade" - debug: msg: "Upgrading database from {{ matrix_postgres_detected_version_corresponding_docker_image }} to {{ matrix_postgres_docker_image_latest }}" diff --git a/roles/matrix-postgres/templates/env-postgres-server.j2 b/roles/matrix-postgres/templates/env-postgres-server.j2 index 34f75aee..06feb82a 100644 --- a/roles/matrix-postgres/templates/env-postgres-server.j2 +++ b/roles/matrix-postgres/templates/env-postgres-server.j2 @@ -1,4 +1,7 @@ #jinja2: lstrip_blocks: "True" POSTGRES_USER={{ matrix_postgres_connection_username }} POSTGRES_PASSWORD={{ matrix_postgres_connection_password }} -POSTGRES_DB={{ matrix_postgres_db_name }} \ No newline at end of file +POSTGRES_DB={{ matrix_postgres_db_name }} +# Synapse refuses to run if collation is not C. +# See https://github.com/matrix-org/synapse/issues/6722 +POSTGRES_INITDB_ARGS=--lc-collate C --lc-ctype C --encoding UTF8