Elixir-Ecto Integration with YugabyteDB

[ashetkar]

Jira Link: DB-2173 This issue tracks all the work related to Elixir-Ecto Integration with YugabyteDB.

Tasks

Done	Name	Notes	Links
✅	Test sample Ecto apps with YugabyteDB	TODO Add Google Doc	sample app
✅	Run Ecto test suite	Failures seen	Integration tests
?	Provide YugabyteDB-specific extension	Savepoint support is coming	existing GH issue
⬜️	Provide example under orm-examples
⬜️	Documentation on Yugabyte site
⬜️	Blog on Yugabyte site

[davidspek]

I believe SAVEPOINT support has been added now, but I'm still seeing an issue with Ecto when it tries to create the schema_migrations table.

[davidspek]

I'm using the latest version of YugabyteDB (2.15.2.0) and ecto 3.4.3. Initially when running the migration it was running fine until this error occured:

13:49:57.604 [info] making create index for table "alertmanager_incidents" nonconcurrent
13:49:57.604 [info] == Migrated 20211003023016 in 13.0s
13:49:57.642 [error] Could not update schema migrations. This error usually happens due to the following:

  * The database does not exist
  * The "schema_migrations" table, which Ecto uses for managing
    migrations, was defined by another library
  * There is a deadlock while migrating (such as using concurrent
    indexes with a migration_lock)

To fix the first issue, run "mix ecto.create".

To address the second, you can run "mix ecto.drop" followed by
"mix ecto.create". Alternatively you may configure Ecto to use
another table for managing migrations:

    config :console, Console.Repo,
      migration_source: "some_other_table_for_schema_migrations"

The full error report is shown below.

13:49:57.651 [info] Postgrex.Protocol (#PID<0.176.0>) disconnected: ** (DBConnection.ConnectionError) client #PID<0.380.0> exited
▸  Evaluation failed with: ERROR 40001 (serialization_failure) Query error: The catalog snapshot used for this transaction has been invalidated.
▸      (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:593: Ecto.Adapters.SQL.raise_sql_call_error/1
▸      (ecto 3.4.6) lib/ecto/repo/schema.ex:661: Ecto.Repo.Schema.apply/4
▸      (ecto 3.4.6) lib/ecto/repo/schema.ex:263: anonymous fn/15 in Ecto.Repo.Schema.do_insert/4
▸      (ecto_sql 3.4.5) lib/ecto/migrator.ex:641: Ecto.Migrator.verbose_schema_migration/3
▸      (ecto_sql 3.4.5) lib/ecto/migrator.ex:293: Ecto.Migrator.async_migrate_maybe_in_transaction/6
▸      (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:875: anonymous fn/3 in Ecto.Adapters.SQL.checkout_or_transaction/4
▸      (db_connection 2.3.1) lib/db_connection.ex:1444: DBConnection.run_transaction/4
▸      (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:702: Ecto.Adapters.SQL.lock_for_migrations/5

After dropping and recreating the database and adding migration_lock: false to our ecto config for our app the following error happens when running the database migration:

15:57:10.529 [info] create index upgrade_policies_name_index
15:57:10.763 [info] making create index for table "upgrade_policies" nonconcurrent
15:57:10.763 [info] == Migrated 20210811183452 in 0.5s
15:57:10.789 [info] == Running 20210907032057 Console.Repo.Migrations.BuildMessageLength.change/0 forward
15:57:10.790 [info] alter table builds
15:57:10.853 [info] == Migrated 20210907032057 in 0.0s
15:57:10.869 [info] == Running 20211003023016 Console.Repo.Migrations.Alertmanager.change/0 forward
15:57:10.869 [info] create table alertmanager_incidents
15:57:15.276 [info] create index alertmanager_incidents_fingerprint_index
▸  Evaluation failed with: ERROR 40001 (serialization_failure) Query error: The catalog snapshot used for this transaction has been invalidated: MISMATCHED_SCHEMA
▸      (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:593: Ecto.Adapters.SQL.raise_sql_call_error/1
▸      (elixir 1.11.4) lib/enum.ex:1411: Enum."-map/2-lists^map/1-0-"/2
▸      (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:686: Ecto.Adapters.SQL.execute_ddl/4
▸      (ecto_sql 3.4.5) lib/ecto/migration/runner.ex:343: Ecto.Migration.Runner.log_and_execute_ddl/3
▸      (ecto_sql 3.4.5) lib/ecto/migration/runner.ex:117: anonymous fn/6 in Ecto.Migration.Runner.flush/0
▸      (elixir 1.11.4) lib/enum.ex:2193: Enum."-reduce/3-lists^foldl/2-0-"/3
▸      (ecto_sql 3.4.5) lib/ecto/migration/runner.ex:116: Ecto.Migration.Runner.flush/0
▸      (stdlib 3.14.1) timer.erl:166: :timer.tc/1