> ## Documentation Index > Fetch the complete documentation index at: https://docs.gcore.com/llms.txt > Use this file to discover all available pages before exploring further. # Replace load balancer pool members > Replaces the full set of pool members with the provided list (declarative, desired-state semantics): members present in the payload are created or updated, members currently on the pool but absent from the payload are deleted. If a member is unchanged (same address + port), it is kept as is without recreation and downtime. If no changes are detected, no task is created and an empty task list is returned. For updating a single existing member without affecting the rest of the pool, use `PATCH /v1/loadbalancers/{project_id}/{region_id}/pools/{pool_id}/members/{member_id}` instead. ## OpenAPI ````yaml /api-reference/services_docs_mintlify_enriched/cloud_api.yaml put /cloud/v1/loadbalancers/{project_id}/{region_id}/pools/{pool_id}/members openapi: 3.1.0 info: title: Gcore OpenAPI – Cloud API description: >- This OpenAPI is an aggregated OpenAPI specification that unifies all Gcore products into a single file. It covers Cloud, CDN, DNS, WAAP, DDoS Protection, Object Storage, Streaming, and FastEdge services. version: 23526a255bc8 servers: - url: https://api.gcore.com security: - APIKey: [] tags: - name: Bare Metal - name: Container as a Service - name: Cost Reports - name: DDoS Protection - name: Everywhere Inference - name: Everywhere Inference Apps - name: File Shares - name: Floating IPs - name: Function as a Service - name: GPU Bare Metal - name: GPU Virtual - name: IP Ranges - name: Images - name: Instances - name: Load Balancers - name: Logging - name: Managed Kubernetes - name: Managed PostgreSQL - name: Networks - name: Placement Groups - name: Ports - name: Projects - name: Quotas - name: Regions - name: Registry - name: Reservations - name: Reserved IPs - name: Routers - name: SSH Keys - name: Secrets - name: Security Groups - name: Snapshot Schedules - name: Snapshots - name: Tasks - name: User Actions - name: User Role Assignments - name: Volumes paths: /cloud/v1/loadbalancers/{project_id}/{region_id}/pools/{pool_id}/members: put: tags: - Load Balancers summary: Replace load balancer pool members description: >- Replaces the full set of pool members with the provided list (declarative, desired-state semantics): members present in the payload are created or updated, members currently on the pool but absent from the payload are deleted. If a member is unchanged (same address + port), it is kept as is without recreation and downtime. If no changes are detected, no task is created and an empty task list is returned. For updating a single existing member without affecting the rest of the pool, use `PATCH /v1/loadbalancers/{project_id}/{region_id}/pools/{pool_id}/members/{member_id}` instead. operationId: LoadBalancerPoolMembersViewSet.put parameters: - in: path name: project_id required: true description: Project ID schema: description: Project ID example: 1 examples: - 1 title: Project Id type: integer - in: path name: region_id required: true description: Region ID schema: description: Region ID example: 1 examples: - 1 exclusiveMinimum: 0 title: Region Id type: integer - in: path name: pool_id required: true description: Pool ID schema: description: Pool ID example: 00000000-0000-4000-8000-000000000000 examples: - 00000000-0000-4000-8000-000000000000 format: uuid4 title: Pool Id type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/PutLbPoolMembersSerializer' responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/TaskIDsSerializer' components: schemas: PutLbPoolMembersSerializer: description: >- New sequence of load balancer pool members. If members are the same (by address + port), they will be kept as is without recreation and downtime. example: - address: 192.168.1.101 instance_id: a7e7e8d6-0bf7-4ac9-8170-831b47ee2ba9 protocol_port: 8000 weight: 2 examples: - - address: 192.168.1.101 instance_id: a7e7e8d6-0bf7-4ac9-8170-831b47ee2ba9 protocol_port: 8000 weight: 2 items: $ref: '#/components/schemas/CreateLbPoolMemberSerializer' title: PutLbPoolMembersSerializer type: array TaskIDsSerializer: properties: tasks: description: >- List of task IDs representing asynchronous operations. Use these IDs to monitor operation progress: - `GET /v1/tasks/{task_id}` - Check individual task status and details Poll task status until completion (`FINISHED`/`ERROR`) before proceeding with dependent operations. example: - d478ae29-dedc-4869-82f0-96104425f565 examples: - - d478ae29-dedc-4869-82f0-96104425f565 items: type: string title: Tasks type: array required: - tasks title: TaskIDsSerializer type: object CreateLbPoolMemberSerializer: properties: address: description: Member IP address example: 192.168.40.33 examples: - 192.168.40.33 format: ipvanyaddress title: Address type: string admin_state_up: default: true description: >- Administrative state of the resource. When set to true, the resource is enabled and operational. When set to false, the resource is disabled and will not process traffic. Defaults to true. example: true examples: - true title: Admin State Up type: boolean backup: default: false description: >- Set to true if the member is a backup member, to which traffic will be sent exclusively when all non-backup members will be unreachable. It allows to realize ACTIVE-BACKUP load balancing without thinking about VRRP and VIP configuration. Default is false. example: true examples: - true - false title: Backup type: boolean instance_id: anyOf: - format: uuid4 type: string - type: 'null' default: null description: Either `subnet_id` or `instance_id` should be provided examples: - a7e7e8d6-0bf7-4ac9-8170-831b47ee2ba9 title: Instance Id monitor_address: anyOf: - format: ipvanyaddress type: string - type: 'null' default: null description: >- An alternate IP address used for health monitoring of a backend member. Default is null which monitors the member address. title: Monitor Address monitor_port: anyOf: - maximum: 65535 minimum: 1 type: integer - type: 'null' default: null description: >- An alternate protocol port used for health monitoring of a backend member. Default is null which monitors the member `protocol_port`. title: Monitor Port protocol_port: description: Member IP port example: 80 examples: - 80 maximum: 65535 minimum: 1 title: Protocol Port type: integer subnet_id: anyOf: - format: uuid4 type: string - type: 'null' default: null description: >- `subnet_id` in which `address` is present. Either `subnet_id` or `instance_id` should be provided examples: - 32283b0b-b560-4690-810c-f672cbb2e28d title: Subnet Id weight: description: >- Member weight. Valid values are 0 < `weight` <= 256, defaults to 1. Controls traffic distribution based on the pool's load balancing algorithm: - `ROUND_ROBIN`: Distributes connections to each member in turn according to weights. Higher weight = more turns in the cycle. Example: weights 3 vs 1 = ~75% vs ~25% of requests. - `LEAST_CONNECTIONS`: Sends new connections to the member with fewest active connections, performing round-robin within groups of the same normalized load. Higher weight = allowed to hold more simultaneous connections before being considered 'more loaded'. Example: weights 2 vs 1 means 20 vs 10 active connections is treated as balanced. - `SOURCE_IP`: Routes clients consistently to the same member by hashing client source IP; hash result is modulo total weight of running members. Higher weight = more hash buckets, so more client IPs map to that member. Example: weights 2 vs 1 = roughly two-thirds of distinct client IPs map to the higher-weight member. example: 1 examples: - 1 exclusiveMinimum: 0 maximum: 256 title: Weight type: integer required: - protocol_port - address title: CreateLbPoolMemberSerializer type: object securitySchemes: APIKey: description: >- API key for authentication. Make sure to include the word `apikey`, followed by a single space and then your token. Example: `apikey 1234_abcdef` type: apiKey in: header name: Authorization ````