Phase 2 Object mode service discovery - CloudMonitor - Cloud Monitor

1. Overview of Object mode

Object mode accesses entities (EntitySet) through a unified SPL interface, calling entity methods to retrieve observability data and metadata. Compared to Table mode (Phase 1), Object mode offers:

Object-oriented: Organizes capabilities around EntitySet with business-aligned semantics.
Dynamic capabilities: Discovers and calls entity methods at runtime (similar to reflection).
Automatic mapping: Applies DataLink and StorageLink field mappings and filters automatically.
Relational semantics: Natively accesses relational data between entities.

Basic syntax:

.entity_set with(domain='domain_name', name='entity_name', [ids|query|other_parameters])
| entity-call method_name(parameters...)

General parameters:

Parameter	Type	Required	Description	Example
domain	string	Yes	Domain of the EntitySet.	‘apm’
name	string	Yes	Name of the EntitySet.	‘apm.service’
ids	array	No	A list of entity IDs.	[‘id1’,‘id2’]
query	string	No	Filter condition. Syntax: SPL syntax.	‘service_id = “xxx”’

Scenarios:

Analyze data by business entity (services, interfaces, hosts).
Automate field mappings and filters to simplify calls.
Reuse unified method semantics across different entities and relationships.

Comparison with Table Mode:

Table mode: Direct access to MetricSet/LogSet/... with finer control, but requires knowledge of underlying details.
Object mode: Entity-centered with method-based capabilities. Higher abstraction and composability.

2. Dynamic capability discovery (runtime method reflection)

Object mode's core is dynamic capability discovery. The built-in __list_method__ enumerates all methods the current EntitySet supports at runtime, including parameter and return value schemas. Call these methods adaptively as needed.

2.1 List available methods

.entity_set with(domain='apm', name='apm.service')
| entity-call __list_method__()

Returned fields:

Field	Description	Example
name	Internal method name for calls.	`get_entity_set`
display_name	Display name.	`Get Current EntitySet`
description	Method description.	`Return the current EntitySet definition`
params	Parameter schema (JSON array).	`[{"key":"dest_entity_set_domain","type":"varchar","display_name":"Destination Entity Domain (empty for all domains)","description":"","required":false}, {...}]`
returns	Return value schema (JSON array).	`[{"key":"entity_set_id","type":"varchar","display_name":"EntitySet id, the format is domain@entity_set@name","description":""},{...}]`

Example method list (excerpt):

name	display_name	description
`__list_method__`	List Available Methods	Lists available methods for the current EntitySet.
`__inspect__`	Configuration Inspector	Checks UModel configuration integrity and validity.
list_data_set	List DataSets	Lists datasets associated with the entity.
list_related_entity_set	List Related EntitySets	Lists entities related to the current entity.
get_golden_metrics	Get Golden Metrics	Gets golden metrics for the entity.
get_metric	Get Metric	Gets metric data from the associated MetricSet.
get_label_values	Get Label Values	Gets tag values from the associated MetricSet.
get_log	Get Log	Gets log data from the associated LogSet.
get_profile	Get Profile	Gets profiling data from the associated ProfileSet.

The return value of __list_method__ varies based on the entity's associated datasets and relationships, enabling adaptive discovery.

2.2 Read method metadata and call adaptively

Typical flow:

Discover capabilities.

.entity_set with(domain='apm', name='apm.service')
| entity-call __list_method__()

Filter and select the target method, such as get_golden_metrics.
Assemble parameters and call the method.

.entity_set with(domain='apm', name='apm.service', query='service_id = "order-service"')
| entity-call get_golden_metrics('range', '1m')

You can also list associated datasets to select a method:

.entity_set with(domain='apm', name='apm.service')
| entity-call list_data_set(['metric_set'], true)

The returned data_set_id and fields_mapping enable automatic parameter and filter assembly for get_metric.

3. Standard flow for capability discovery and calls

Specify the entity context: domain and name, with optional ids or query.
Enumerate available methods: __list_method__().
Read the method signature, which includes params and returns (JSON description).
Select a method and prepare parameters. If necessary, use list_data_set and list_related_entity_set.
Execute the entity-call to retrieve data or an SPL statement. In DryRun mode, the call returns an SPL statement.

Note:

If no datasets or relationships are associated, only basic methods (__list_method__ and __inspect__) are returned.
Method availability and parameters depend on the entity's associated DataSets and Links.

4. Typical usage examples

4.1 Discover available methods for an entity

.entity_set with(domain='apm', name='apm.service')
| entity-call __list_method__()

4.2 Get golden metrics (based on discovery results)

.entity_set with(domain='apm', name='apm.service', query='service_id = "order-service"')
| entity-call get_golden_metrics('range', '1m')

4.3 Query associated datasets and continue calls

.entity_set with(domain='apm', name='apm.service')
| entity-call list_data_set(['metric_set'], true)

Based on the return value:

Field	Description
data_set_id	Unique identifier of the associated dataset, such as `apm@metric_set@apm.metric.apm.service`.
type	Dataset type, such as `metric_set`.
fields_mapping	Field mapping that guides automatic parameter and filter assembly.

Proceed with a call like:

.entity_set with(domain='apm', name='apm.service', query='service_id = "order-service"')
| entity-call get_metric('apm', 'apm.metric.apm.service', 'request_count', 'range', '1m')

5. Best practices

Discover first, then call: Use __list_method__() to determine available capabilities before calling methods.
Combine list_data_set and list_related_entity_set to automate the construction of parameters and filter conditions.
Use DryRun for debugging:

.set "umodel_paas_mode"='dry_run';

.entity_set with(domain='apm', name='apm.service')
| entity-call get_metric('apm', 'apm.metric.apm.service', 'request_count')

DryRun returns an executable SPL statement for reviewing field mappings and query generation.

Cache the method list: The list is relatively stable. Cache it application-side to improve performance.