Fix concurrent indexes migration (#3591)

Author: r4victor

src/dstack/_internal/server/migrations/env.py

@@ -73,7 +73,7 @@ def run_migrations(connection: Connection):
         # lock_timeout is needed so that migrations that acquire locks
         # do not wait for locks forever, blocking live queries.
         # Better to fail and retry a deployment.
-        connection.execute(text("SET lock_timeout='10s';"))
+        connection.execute(text("SET lock_timeout='15s';"))
     connection.commit()
     context.configure(
         connection=connection,

src/dstack/_internal/server/migrations/versions/2026/02_18_1122_a8ed24fd7f90_add_pipeline_indexes_for_compute_and_.py

@@ -19,6 +19,21 @@
 def upgrade() -> None:
     # ### commands auto generated by Alembic - please adjust! ###
     with op.get_context().autocommit_block():
+        if op.get_context().dialect.name == "postgresql":
+            # Concurrent index ops can fail midway, leaving invalid indexes behind.
+            # Use DROP INDEX IF EXISTS so the migration can be retried safely.
+            op.drop_index(
+                "ix_compute_groups_pipeline_fetch_q",
+                table_name="compute_groups",
+                if_exists=True,
+                postgresql_concurrently=True,
+            )
+            op.drop_index(
+                "ix_placement_groups_pipeline_fetch_q",
+                table_name="placement_groups",
+                if_exists=True,
+                postgresql_concurrently=True,
+            )
         op.create_index(
             "ix_compute_groups_pipeline_fetch_q",
             "compute_groups",
@@ -47,11 +62,13 @@ def downgrade() -> None:
         op.drop_index(
             "ix_placement_groups_pipeline_fetch_q",
             "placement_groups",
+            if_exists=True,
             postgresql_concurrently=True,
         )
         op.drop_index(
             "ix_compute_groups_pipeline_fetch_q",
             "compute_groups",
+            if_exists=True,
             postgresql_concurrently=True,
         )
     # ### end Alembic commands ###