Add DB index for instance_health_checks (#4288)

Author: r4victor

src/dstack/_internal/server/migrations/versions/2026/09_14_0656_40f19bea9d2a_add_ix_instance_health_checks_instance_.py

@@ -0,0 +1,44 @@
+"""Add ix_instance_health_checks_instance_id_collected_at
+
+Revision ID: 40f19bea9d2a
+Revises: 652af7a3c9c9
+Create Date: 2026-09-14 06:56:41.088290+00:00
+
+"""
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "40f19bea9d2a"
+down_revision = "652af7a3c9c9"
+branch_labels = None
+depends_on = None
+
+INDEX_NAME = "ix_instance_health_checks_instance_id_collected_at"
+TABLE_NAME = "instance_health_checks"
+
+
+def _drop_index() -> None:
+    op.drop_index(
+        INDEX_NAME,
+        table_name=TABLE_NAME,
+        if_exists=True,
+        postgresql_concurrently=True,
+    )
+
+
+def upgrade() -> None:
+    with op.get_context().autocommit_block():
+        _drop_index()
+        op.create_index(
+            INDEX_NAME,
+            TABLE_NAME,
+            ["instance_id", "collected_at"],
+            unique=False,
+            postgresql_concurrently=True,
+        )
+
+
+def downgrade() -> None:
+    with op.get_context().autocommit_block():
+        _drop_index()

src/dstack/_internal/server/models.py

@@ -1061,6 +1061,14 @@ class InstanceHealthCheckModel(BaseModel):
     status: Mapped[HealthStatus] = mapped_column(EnumAsString(HealthStatus, 100))
     response: Mapped[str] = mapped_column(Text)
 
+    __table_args__ = (
+        Index(
+            "ix_instance_health_checks_instance_id_collected_at",
+            instance_id,
+            collected_at,
+        ),
+    )
+
 
 class VolumeModel(PipelineModelMixin, BaseModel):
     __tablename__ = "volumes"