fix(BA-1610): Use correct attribute routings instead of routes for endpoints

[rapsealk]

Follow-up of #4109 and resolves #4755 (BA-1610)

This pull request fixes an issue with the incorrect usage of an attribute name in the codebase. The attribute routes has been replaced with the correct attribute routings to ensure proper functionality.

Fixes to attribute usage:

• changes/.fix.md: Updated documentation to specify the correct attribute routings instead of routes for endpoints.
• src/ai/backend/manager/services/model_serving/services/model_serving.py: Updated the update_route method to use endpoint.routings instead of endpoint.routes when filtering for healthy routes.

backend.ai/src/ai/backend/manager/models/endpoint.py

Lines 103 to 238 in 363e702

	class EndpointRow(Base):
	__tablename__ = "endpoints"
	__table_args__ = (
	CheckConstraint(
	sa.or_(
	sa.column("lifecycle_stage") == EndpointLifecycle.DESTROYED.value,
	sa.column("image").isnot(None),
	),
	name="ck_image_required_unless_destroyed",
	),
	)
	id = EndpointIDColumn()
	name = sa.Column("name", sa.String(length=512), nullable=False)
	created_user = sa.Column("created_user", GUID, nullable=False)
	session_owner = sa.Column("session_owner", GUID, nullable=False)
	# minus session count means this endpoint is requested for removal
	replicas = sa.Column("replicas", sa.Integer, nullable=False, default=0, server_default="0")
	image = sa.Column("image", GUID)
	model = sa.Column(
	"model",
	GUID,
	sa.ForeignKey("vfolders.id", ondelete="SET NULL"),
	nullable=True,
	)
	model_mount_destination = sa.Column(
	"model_mount_destination",
	sa.String(length=1024),
	nullable=False,
	default="/models",
	server_default="/models",
	)
	domain = sa.Column(
	"domain",
	sa.String(length=64),
	sa.ForeignKey("domains.name", ondelete="RESTRICT"),
	nullable=False,
	)
	project = sa.Column(
	"project",
	GUID,
	sa.ForeignKey("groups.id", ondelete="RESTRICT"),
	nullable=False,
	)
	resource_group = sa.Column(
	"resource_group",
	sa.ForeignKey("scaling_groups.name", ondelete="RESTRICT"),
	index=True,
	nullable=False,
	)
	lifecycle_stage = sa.Column(
	"lifecycle_stage",
	EnumValueType(EndpointLifecycle),
	nullable=False,
	default=EndpointLifecycle.CREATED,
	)
	tag = sa.Column("tag", sa.String(length=64), nullable=True)
	startup_command = sa.Column("startup_command", sa.Text, nullable=True)
	bootstrap_script = sa.Column("bootstrap_script", sa.String(length=16 * 1024), nullable=True)
	callback_url = sa.Column("callback_url", URLColumn, nullable=True, default=sa.null())
	environ = sa.Column("environ", pgsql.JSONB(), nullable=True, default={})
	open_to_public = sa.Column("open_to_public", sa.Boolean, default=False)
	runtime_variant = sa.Column(
	"runtime_variant",
	StrEnumType(RuntimeVariant),
	nullable=False,
	default=RuntimeVariant.CUSTOM,
	)
	model_definition_path = sa.Column("model_definition_path", sa.String(length=128), nullable=True)
	resource_slots = sa.Column("resource_slots", ResourceSlotColumn(), nullable=False)
	url = sa.Column("url", sa.String(length=1024))
	resource_opts = sa.Column("resource_opts", pgsql.JSONB(), nullable=True, default={})
	cluster_mode = sa.Column(
	"cluster_mode",
	sa.String(length=16),
	nullable=False,
	default=ClusterMode.SINGLE_NODE,
	server_default=ClusterMode.SINGLE_NODE.name,
	)
	cluster_size = sa.Column(
	"cluster_size", sa.Integer, nullable=False, default=1, server_default="1"
	)
	extra_mounts = sa.Column(
	"extra_mounts",
	StructuredJSONObjectListColumn(VFolderMount),
	nullable=False,
	default=[],
	server_default="[]",
	)
	retries = sa.Column("retries", sa.Integer, nullable=False, default=0, server_default="0")
	created_at = sa.Column(
	"created_at",
	sa.DateTime(timezone=True),
	server_default=sa.text("now()"),
	nullable=True,
	)
	destroyed_at = sa.Column(
	"destroyed_at",
	sa.DateTime(timezone=True),
	nullable=True,
	)
	routings = relationship("RoutingRow", back_populates="endpoint_row")
	tokens = relationship(
	"EndpointTokenRow",
	back_populates="endpoint_row",
	primaryjoin="foreign(EndpointTokenRow.endpoint) == EndpointRow.id",
	)
	endpoint_auto_scaling_rules = relationship(
	"EndpointAutoScalingRuleRow", back_populates="endpoint_row"
	)
	image_row = relationship(
	"ImageRow",
	primaryjoin=lambda: foreign(EndpointRow.image) == ImageRow.id,
	foreign_keys=[image],
	back_populates="endpoints",
	)
	model_row = relationship("VFolderRow", back_populates="endpoints")
	created_user_row = relationship(
	"UserRow",
	back_populates="created_endpoints",
	foreign_keys=[created_user],
	primaryjoin=lambda: foreign(EndpointRow.created_user) == UserRow.uuid,
	)
	session_owner_row = relationship(
	"UserRow",
	back_populates="owned_endpoints",
	foreign_keys=[session_owner],
	primaryjoin=lambda: foreign(EndpointRow.session_owner) == UserRow.uuid,
	)

Checklist: (if applicable)

• Milestone metadata specifying the target backport version
• Mention to the original issue

[Copilot]

Pull Request Overview

This PR corrects the use of the endpoint attribute by replacing all references from routes to routings to ensure the filtering logic uses the intended field.

• Update code in update_route to use endpoint.routings instead of endpoint.routes
• Amend the changelog in changes/.fix.md to document the correct attribute

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/ai/backend/manager/services/model_serving/services/model_serving.py	Replace endpoint.routes with endpoint.routings for healthy-route filtering
changes/.fix.md	Document the switch from routes to routings

[fregataa]

LGTM

[HyeockJinKim]

It seems like there's a problem with insufficient test codes..