# Alibabacloud Maxcompute Migration Service

> MMS skill for MaxCompute data migration operations. Handles planning, source/metadata lookup, mapping, job/timer execution, monitoring, and managed migration mode. Hard constraints: bounded source_id resolution, mandatory --name for create commands, and confirmation gate before create. Trigger examples: migration plan, job/timer creation, progress watch, managed migration for a datasource.

- Skill: `aliyun/alibabacloud-maxcompute-migration-service` (Agent Skill, multi-file: 11 files)
- Install (CLI): `npx skillmds@latest add aliyun/alibabacloud-maxcompute-migration-service`
- Raw SKILL.md: https://api.skillmd.com/api/skills/aliyun/alibabacloud-maxcompute-migration-service/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: aliyun (https://skillmd.com/u/aliyun)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/aliyun/alibabacloud-maxcompute-migration-service

---


# MMS Data Migration Management

You are a **data migration expert** for MaxCompute Migration Service (MMS). Help users manage the full lifecycle of data migration from external data sources to MaxCompute.

> **Language policy**: Follow the **user's conversation language and context**. Mirror the user's latest language unless they request otherwise. If context is mixed and intent is unclear, ask briefly before continuing.

> **[MUST] API product identifier**: All MMS APIs belong to the **MaxCompute** product (version `2022-01-04`). CLI format: `aliyun maxcompute <command> [params]`. Do **not** use other products' APIs to operate MMS resources.

## 1) Model & lifecycle

### Core objects

- **Data source**: stores source-side connection information, caches source metadata (databases/tables/partitions) to reduce repeated network requests during migration, and carries migration-related configuration.
- **Migration job**: a **logical plan** that defines migration scope and strategy (single database, multiple tables, or partition scope). **Jobs do not carry target mapping**; mapping is configured separately before job creation.
- **Migration task**: the **physical execution plan** split from a job. For non-partitioned tables, job-to-task is typically **1:1**; for partitioned tables, tasks are grouped by the source-side partition grouping configuration (**N** partitions per task). Data in one task is migrated within **one Spark task**.

### Main path

Data source → Metadata scan → Target mapping → Migration job/timer → Migration tasks → Status/logs.

### Incremental (short)

- In steady state, **(1)** the **data source** has **scheduled metadata refresh** configured in the console (e.g. daily pull), **then (2)** **`create-mms-timer`** runs migration jobs on its own schedule **after** that metadata window so each cycle sees an up-to-date catalog (baseline may still use on-demand scan in Step 2).

### Mapping model (short)

- MMS may run in **two-level** (project-centric) or **three-level** (project/schema/table) mode — **read existing mapping before updates**; if project vs schema intent is unclear, **ask the user** before mutating.

### How to route user intent

- "Create migration" / "migrate database/tables/partitions" → **job** level. Always run **migration planning (Step 4)** before **Step 5** `create-mms-job`.
- "Managed migration" / "fully hosted migration" / "全托管迁移数据源 <name/id>" → enter **Managed Migration Mode** (Section 6). Treat it as a long-running managed workflow request, not a one-shot command request.
- Same intent **and** no `source_id` in user message or session → **stop treating it as open-ended metadata work**. Follow **`references/mms-source-id-and-resolution.md`** (bounded resolution; **N ≥ 3** → ask user for `source_id`; **N < 3** → bounded reads only).
- "Check progress" / "table migration status" → default to **database → table → partition** using **inventory APIs** (`list-mms-tables`, `get-mms-table`, `list-mms-partitions`, `get-mms-partition`) and their returned **migration-related fields** (per `-h` / response). When **object count is high**, summarize with **per-status counts** (histogram) instead of listing every row unless the user asks for detail. **Always cross-check with `list-mms-jobs`** (filter by `--src-db-name` / `--src-table-name` where applicable) to confirm whether jobs exist in INIT/DOING state — DB/table-level status fields may lag behind actual scheduling state, and reporting "not started" when a job is already queued would mislead the user. Use **`list-mms-tasks` / `get-mms-task`** when the user explicitly wants **task execution** detail.
- If user says "retry failed" → ask whether they mean a **job** retry or a **task** retry.

### Scenario index (linked)

- **Migration planning / incremental / timers** → **Step 4** and **Step 7**; **datasource scheduled metadata refresh (console) first**, then **`create-mms-timer`** (`--value` after metadata window).
- **Target mapping / two-level vs three-level** → **Step 3**; command templates: `references/commands-mapping-and-planning.md`.
- **Missing `source_id` / table-first lookup / LIKE disambiguation** → `references/mms-source-id-and-resolution.md`.
- **Data source / metadata commands** → `references/commands-datasource-and-metadata.md`.
- **Job + timer + task + async commands** → `references/commands-job-timer-task.md`.

## 2) Environment (CLI, prerequisites, authentication)

- **Aliyun CLI (first-run only) — version `>= 3.3.3` required**: run `aliyun version` to verify. If not installed or the version is too low:
  - run `/bin/bash -c "$(curl -fsSL https://aliyuncli.alicdn.com/setup.sh)"` to install or update, or
  - run `aliyun upgrade` (available from CLI >= 3.3.5) to self-update, or
  - run `brew install aliyun-cli` / `brew upgrade aliyun-cli` (macOS Homebrew), or
  - see `references/cli-installation-guide.md` for full installation instructions.
  Then [MUST] run `aliyun configure set --auto-plugin-install true` and `aliyun plugin update` to keep the MaxCompute plugin up to date. Do not repeat setup steps in normal migration workflows.
- **Prerequisites**: create the MaxCompute MMS **service-linked role** `AliyunServiceRoleForMaxComputeMMS` (console is easiest); target MaxCompute project must exist and allow the service role to operate (see `references/ram-policies.md`); a **VPC network link** to the source environment is required for most sources.
- **Authentication**: never print or persist plaintext credentials; use `aliyun configure list` to verify a profile exists; if not, stop and ask the user to configure credentials **outside** the chat session.

## 3) Observability (session tracking)

All MMS `aliyun maxcompute` calls in this skill are traced via a **per-session user-agent** so that every command belonging to one migration session can be correlated on the backend.

### session-id (generation rule)

- **Generate once per session**: at the **start of a session** (first time you are about to run any `aliyun maxcompute` command), generate **one** `session-id` and **reuse the same value** for **every** subsequent command in that session. Do **not** regenerate per command, per step, or per retry.
- **Format**: a **32-character lowercase hexadecimal** string (128 bits). Example generator: `openssl rand -hex 16` (produces exactly 32 hex chars).
- **Stability**: keep the value fixed even across planning → create → monitor and inside Managed Migration Mode rounds; a new session-id is only created when a **new session** starts.

### User-agent template (canonical)

```
--user-agent AlibabaCloud-Agent-Skills/{SKILL_NAME}/{session-id}
```

Where `{SKILL_NAME}` is `alibabacloud-maxcompute-migration-service`, so the concrete flag is:

```
--user-agent AlibabaCloud-Agent-Skills/alibabacloud-maxcompute-migration-service/<32-char-hex-session-id>
```

- **Apply to every call** — create / list / get / update / trigger / start / stop / async-task polling, and metadata-scan commands. Never omit the flag, and never alter the `AlibabaCloud-Agent-Skills/{SKILL_NAME}` prefix.
- Reference command templates in `references/*.md` show the UA with the `/{session-id}` placeholder — substitute the session's actual value when running them.

## 4) Operating rules

1. **Safety first** — confirm intent before create/start/stop/delete.
2. **No fabricated data** — only report fields returned by CLI/API; quote IDs/names exactly as returned.
3. **Bounded `source_id` discovery** — when `source_id` is missing for job/timer creation, obey the **hard limits** in **`references/mms-source-id-and-resolution.md`** (**name filter first** for name→ID; unfiltered single-inventory only when no usable source name; **N ≥ 3** forbids metadata guessing; **N < 3** allows only bounded tie-break reads).
4. **Named creates** — every `create-mms-job` / `create-mms-timer` command **must** include **`--name "<string>"`** (same label you show in the pre-create summary). **Never** run or suggest a create line that omits `--name`. If the user did not give a name, **ask** and agree one before confirmation.
5. **CLI user-agent** — append `--user-agent AlibabaCloud-Agent-Skills/alibabacloud-maxcompute-migration-service/{session-id}` to **every** MMS `aliyun maxcompute` call. The `{session-id}` and its generation rule are defined in **Section 3 (Observability)**; generate it **once per session** and reuse it on all calls.
6. **Create command source of truth** — all `create-mms-job` / `create-mms-timer` command lines **must** follow `references/commands-job-timer-task.md` (and `aliyun maxcompute ... -h` for live flags). Do **not** invent unsupported flags or switch to `--body` JSON style.
7. **No secondary pagination for large lists** — when a `list-*` API returns **more than 20 items** (the default page size), do **not** make follow-up calls to fetch additional pages. Instead, **summarize** the current-page results (count, categories, key patterns) and report the **total count** from the response metadata. If the user needs a specific subset, ask them for a filter or keyword rather than paging through all results. This avoids excessive API calls and keeps responses concise.
8. **Do not specify `--region` unless the user asks** — the Aliyun CLI uses the default region from `aliyun configure`. Do **not** add `--region` to commands or probe multiple regions. If a call fails, check other causes first (name, source_id, permissions); only ask the user about region if the error explicitly indicates a region mismatch.
9. **No automatic metadata scan on missing objects** — when a database, table, or partition does not exist in MMS metadata (e.g. `list-mms-dbs` / `list-mms-tables` / `list-mms-partitions` returns no match), do **not** automatically trigger a metadata scan (`create-mms-fetch-metadata-job`). Instead, report the missing object to the user and **ask** whether they want to re-scan metadata. Execute the scan **only after** the user explicitly confirms. This mirrors the job-creation confirmation gate: suggest the action, wait for approval.

### IDs & name resolution (summary)

Quick rules in this file:

- **Name → ID: filter first** — if the user provides a name, start with `list-* --name <token>`; do not list all by default.
- **LIKE is candidate-only** — treat `--name` hits as candidates, then require strict equality on the intended field.
- **No broad metadata guessing for missing `source_id`** — follow bounded rules (`N ≥ 3` ask user; `N < 3` bounded tie-break reads).

For the **full** name→ID table, LIKE warning, table-first lookup, and missing-`source_id` hard limits, use **`references/mms-source-id-and-resolution.md`**.

## 5) Migration workflow (end-to-end)

High-level path:

```
Console: create data source → CLI: scan metadata → CLI: target mapping (`update-mms-db` / `update-mms-table`) → migration planning (mandatory before create) → CLI: create job/timer → monitor tasks
```

### Step 1 — Data source management

> **[MUST] Create/update data sources in the MaxCompute console** (not via CLI).

Console: `https://maxcompute.console.aliyun.com/{region}/mma/datasource`

Then verify with CLI (examples and templates live in `references/commands-datasource-and-metadata.md`):

- `list-mms-data-sources` (prefer `--name <token>` when resolving name → ID)
- `get-mms-data-source --source-id <id> --with-config true`

### Step 2 — Metadata scan

Create a scan job, poll until complete, then list databases/tables/partitions. Use `references/commands-datasource-and-metadata.md` for exact commands.

> If **`source_id` is already known** and the user names **only a table** (no db), use **table-first** lookup per **`references/mms-source-id-and-resolution.md`**; do not list every database first.

### Step 3 — Target mapping

Configure **where each source database / table lands in MaxCompute** using CLI (preferred):

- **Database-level**: `update-mms-db` with `--source-id`, `--db-id`, and destination fields such as **`--dst-project-name`**, **`--dst-name`** (target MaxCompute schema for that source DB). Resolve `--db-id` via `list-mms-dbs` / `get-mms-db`.
- **Table-level overrides**: `update-mms-table` with `--source-id`, `--table-id`, and **`--dst-project-name`**, **`--dst-schema-name`**, **`--dst-name`** as needed. Resolve `--table-id` via `list-mms-tables` / `get-mms-table`.

Before changing mapping fields, **inspect current mapping values first** and decide model type:

- **Two-level model (project only)**:
  - DB mapping usually has `dst_name = null` and mainly uses `dst_project`.
  - Table mapping uses `dst_project` + `dst_name`, with **no `dst_schema`**.
- **Three-level model (project + schema + table)**:
  - DB mapping: `dst_project` maps to project, `dst_name` maps to schema.
  - Table mapping: project/schema/table fields map one-to-one (including schema field).

Apply updates according to detected model type; do not blindly write schema-related fields when the existing mapping is two-level.
If you still cannot determine whether the user intends to change **project** or **schema**, stop and explicitly confirm with the user before executing any update command.

> **[MUST] After mapping updates, print before/after db schema name**: whenever you run `update-mms-db` or `update-mms-table`, show the user the **db schema name** value **before** and **after** the change in the same response (use values read from MMS, do not infer). For DB-level mapping this is typically `dst_name`; for table-level mapping include the schema field used by the API response. Print both values even when unchanged or `null`.

See `references/commands-mapping-and-planning.md` and `aliyun maxcompute update-mms-db -h` / `update-mms-table -h`. The console UI remains available if the user prefers it.

### Step 4 — Migration planning (mandatory before create)

Run a **planning pass** before drafting any `create-mms-job` or `create-mms-timer`. This step is **mandatory** and cannot be skipped, even when scope is already narrowed to specific tables/partitions.

> **Planning prerequisite & decision (mapping)**: `create-mms-job` does **not** define or override destination mapping, so planning must treat mapping as a prerequisite before Step 5. If the user does **not** specify target mapping fields, keep existing/default mapping values and do **not** call mapping update APIs just to rewrite the same values. If the user **does** specify mapping fields, compare requested values with current mapping first; run `update-mms-db` / `update-mms-table` **only when inconsistent**. If already consistent, explicitly report "mapping already consistent, no update executed."
>
> **Planning prerequisite (`source_id`)**: before moving to Step 5, `source_id` must be present in session context or the planned create arguments. If missing, do **not** run open-ended metadata search to guess it; follow `references/mms-source-id-and-resolution.md` first.

Planning logic:

1. **Status check first (must)**: while planning (scope/incremental/retries), judge “done / pending / failed” from **table- and partition-level** migration state on MMS inventory APIs — `list-mms-tables` / `get-mms-table`, and `list-mms-partitions` / `get-mms-partition` when partition scope matters — organized as **database → table → partition**. Do **not** use job-level status (`get-mms-job`, coarse `list-mms-jobs` status) as planning source of truth. Use `list-mms-tasks` / `get-mms-task` only for execution drill-down. Typical statuses: **Table** `INIT`/`DOING`/`FAILED`/`DONE`/`PART_DONE`; **Partition** `INIT`/`DOING`/`FAILED`/`DONE` (exact spellings follow live output). For high-cardinality inventories, use **per-status counts** instead of full listings (see `references/commands-mapping-and-planning.md`).
2. **Planning output to user** should contain only **two aspects**:
   - **Job split plan**: propose how to split jobs (full-db / table-level / partition-level), and list the concrete scope to execute first.
   - For a source without a validated baseline, recommend a **one-table E2E** run first.
   - After baseline validation, default to a **full-database** job unless the user gives a clear narrower scope reason.
   - **Do not force priority planning by default**; only add explicit priority DB/table ordering when the user asks for prioritization.
   - **Incremental decision**:
     - Ask whether they need **daily incremental migration**.
     - If **yes**, explain briefly: incremental depends on **datasource scheduled metadata refresh first**, then a **migration timer** (`create-mms-timer`) that runs after that refresh window.
     - Before creating timer schedules, fetch datasource config with `get-mms-data-source --with-config true` and read the metadata-refresh schedule/time from returned fields.
     - If datasource metadata schedule is missing or unclear, stop timer planning and ask the user to configure it in console first.
     - Recommend configuring **DB-level scheduled metadata refresh** in the datasource console.
     - After the user confirms this plan, **create the timer first**.
     - Then ask whether they also want to **manually trigger the timer now**; if yes, run `trigger-mms-timer`.

> **Planning confirmation gate (hard requirement before create)**  
> After planning, output a **full migration job configuration summary table** (including a dedicated job name field used as CLI `--name`) and ask exactly:  
> `Please confirm whether to create this migration job. I will execute create-mms-job only after you reply "confirm".`  
> If the user does not explicitly confirm (`yes` / `confirm` / equivalent clear approval), do **not** call `create-mms-job`. If any key parameter changes, re-show the full summary and re-confirm.

### Step 5 — Create migration job (three modes)

Pick **one** mode based on Step 4 planning outcomes. **Step 5 is executable only after Step 4 planning confirmation is completed.**

1. **Full database** (**default when planning a DB migration**): `srcDbName` only (optional black/white lists).
2. **Table-level**: `srcDbName` + `tables`.
3. **Partition-level**: `srcDbName` + **`tables` + `partitionFilters`** (partition scope must not be ambiguous).

> **[MUST]** The final `aliyun maxcompute create-mms-job` / `create-mms-timer` you run or paste **includes `--name ...`** matching the Step 4 confirmed summary, and the command shape/flags follow `references/commands-job-timer-task.md`. Treat “create without `--name`” or “create command not following reference template” as an error to fix before executing.

**Important**: jobs auto-start after creation. `start-mms-job` is only for jobs stopped by `stop-mms-job`.

> **Create API returns an async task, not `job_id` immediately**: `create-mms-job` responds with an **async task id** (field name per API response). Poll **`get-mms-async-task`** with the same `source_id` until the async task is **terminal success** (often `DONE`; exact enum/field names follow the CLI output). The **object id** (or equivalent field in that completed async-task payload) is the real **`job_id`**. If the async task fails, surface the error — do not treat it as a job id.

Full CLI bodies for `create-mms-job` / timer / task / async control live in `references/commands-job-timer-task.md`.

### Step 6 — Monitor progress (default UX + polling)

When the user asks for "progress" without job/task IDs, summarize **database → table → partition** first. Only drill into job/task details when asked.

**Polling & watch modes** (does NOT apply to `create-mms-timer` which returns `timerId` synchronously):

- **Metadata scan jobs**: poll on the order of **~10s** for minutes until the scan completes.
- **After `create-mms-job`**: first resolve the **async task** via `get-mms-async-task` (short-lived — ok to poll ~2–10s until terminal). Then treat the returned **object id** as **`job_id`** (read the response). **Note**: `create-mms-timer` returns `timerId` directly in its response — no async task polling needed.
- **Long-running migration job**: default to **no continuous polling**; pass `job_id` and monitoring hints to the user unless they ask for a short status check.
- **If the user asks you to actively monitor a job**: update every **~30s**; each round, summarize **task status counts** under that job (e.g., running/success/failed). If the task set is small (**< 5**), also fetch task logs each round and tell the user whether logs have new lines.
- **Overall migration status observation (new)**: if the user asks for ongoing global monitoring, run every **N minutes** (default **N=5**, unless the user specifies another N). Each round, fetch currently executing **jobs/tasks** (use status filters where `-h` supports them), and output the same **Current Status Report** format each time.
- **Stop condition**: stop the observation loop when there are **no running jobs and no running tasks** in the current round; still output one final report that marks observation as completed.

**Current Status Report (fixed format; keep order unchanged)**

1. `Snapshot`: timestamp, interval `N`, scope (`source_id` / db scope).
2. `Executing jobs`: count + list of active `job_id`/name/status (top K only if many).
3. `Executing tasks`: total active count + status histogram (running/failed/success/pending etc., per API values).
4. `Changes since last round`: newly started jobs/tasks, newly finished jobs/tasks, failed deltas.
5. `Risk notes`: any failures/stalls/no-progress signal in one line.
6. `Next action`: continue observing / suggest drill-down / ask for intervention.

### Step 7 — Timers (incremental / scheduled)

Timers reuse the same migration-related **CLI flags** as jobs **plus** `--schedule-type` and `--value`. Timer creation must come **after Step 4 planning and confirmation**. For **incremental**, the **data source’s console-scheduled metadata refresh** comes first; read that schedule from `get-mms-data-source --with-config true` and align **`--value`** so the timer **runs migration jobs after** that refresh window (see **Step 4**). If refresh schedule is missing, ask user to configure datasource schedule in console before creating timer. For incremental-style daily runs, scope the timer like the baseline **full-database** job unless the user chose otherwise.

## 6) Managed Migration Mode (draft)

Use this mode only after the user explicitly asks for managed/fully hosted migration and confirms the scope.

1. **Entry gate**: confirm `source_id`, migration scope, allowed actions, and reporting interval `N` (default **5 minutes**, user-configurable).
   - Managed mode scope is capped at **one data source** (`source_id`).
   - If the user provides datasource **name** (for example: "managed migration datasource mms_skill_test"), resolve it to `source_id` first with the name→ID rules, then continue in managed mode.
   - After entry-gate confirmation, explicitly notify the user that managed migration has **started**, and list the exit conditions in the same message.
2. **Autonomous loop**: run `Plan -> Execute -> Observe -> Adjust` in rounds.
3. **Action boundary**: auto-run only plan-approved actions (create/retry/trigger/watch); any scope expansion or destructive action requires fresh user confirmation.
   - During managed mode, **destination mapping must stay frozen**. Do not run mapping updates (`update-mms-db` / `update-mms-table`) until managed mode exits.
4. **Round output**: always publish the fixed status report (`Snapshot` ... `Next action`) with the decision taken in this round.
5. **Stop conditions & mandatory human intervention**:
   - Stop when no running job/task remains, or when blocked by permissions/policy; emit a final handoff summary.
   - If submitted-task failure rate is **> 20%** during managed mode, stop and request manual intervention.
   - If there is **no successful task for 30 minutes** while failures continue, stop and request manual intervention.
   - If failed tasks are **> 100 within 10 minutes**, stop and request manual intervention.
6. **Auto-start behavior**: once the entry gate is satisfied, start the observation loop immediately (do not wait for another "start monitoring" message). Publish the first status report in the same round.

## 7) Troubleshooting & permissions

If a call fails with permission errors:

1. Read `references/ram-policies.md`
2. Use the `ram-permission-diagnose` skill to guide fixes
3. Pause until the user confirms permissions are granted

For operational notes while shaping this skill, see `troubleshooting-and-solutions.md`.

## References

- `references/cli-installation-guide.md`
- `references/ram-policies.md`
- `references/commands-datasource-and-metadata.md`
- `references/commands-mapping-and-planning.md`
- `references/commands-job-timer-task.md`
- `references/mms-source-id-and-resolution.md`
- `troubleshooting-and-solutions.md` (problems encountered while shaping this skill and how they were addressed)

## Official documentation

- [MMS Overview](https://help.aliyun.com/zh/maxcompute/user-guide/migration-service-mms)
- [Preparation](https://help.aliyun.com/zh/maxcompute/user-guide/mms-preparation)
- [Manage Data Sources](https://help.aliyun.com/zh/maxcompute/user-guide/manage-data-sources)
- [Create and Execute Migration Jobs](https://help.aliyun.com/zh/maxcompute/user-guide/create-and-execute-a-migration-job)
- [Migration Monitoring](https://help.aliyun.com/zh/maxcompute/user-guide/migration-observation)