docs: record pending CouchDB robustness improvement

Releasing 1.0.15

docs/adr/2026_08_couchdb_remote_connection_ownership.md

@@ -0,0 +1,329 @@
+# Architectural Decision Record: CouchDB Remote Connection Ownership
+
+## Status
+
+Accepted. The first implementation is deliberately limited to the
+abort-capable CouchDB connectivity preflight used by one-shot replication.
+
+## Context
+
+Commonlib opens a remote CouchDB database through `RemoteService.connect()`.
+Before this decision, a successful call returned only a PouchDB handle and an
+information snapshot:
+
+```typescript
+{
+    db: PouchDB.Database<EntryDoc>;
+    info: PouchDB.Core.DatabaseInfo;
+}
+```
+
+The value did not state who must close the handle or how requests which outlive
+the current operation are cancelled. Callers consequently accumulated their
+own `try`/`finally` blocks and closing helpers. Commonlib PR 112 made finite
+handle clean-up substantially safer, but closing a raw PouchDB handle still did
+not define ownership of its outstanding HTTP work.
+
+A remote PouchDB HTTP handle is not a dedicated socket. `db.close()` emits
+PouchDB's normal `closed` event and closes the logical handle, but the HTTP
+adapter does not establish that a pending browser fetch or response-body read
+has stopped. `RemoteService.performFetch()` also records a physical request as
+complete once response headers have arrived, while PouchDB may still be reading
+and parsing the body. Neither the request counters nor raw `db.close()` can
+therefore prove that the transport work has settled.
+
+One-shot CouchDB replication performs the following work before it creates the
+replication controller:
+
+1. prepare the encryption security seed;
+2. construct the remote PouchDB handle and read database information;
+3. check and, where required, migrate the remote database version;
+4. read and update compatibility Metadata, including the milestone document;
+   and
+5. create the PouchDB replication operation.
+
+The controller owned by `processSync()` begins only at step 5. A request which
+never settles during steps 2 to 4 is outside that cancellation scope. The
+shared one-shot result remains pending as well, so later triggers join the same
+pending operation rather than beginning a fresh attempt.
+
+Self-hosted LiveSync issue 1116 provides evidence of this failure shape. On one
+Linux and Electron combination, a one-shot attempt remained pending while
+writing the remote milestone document. Bypassing that write allowed the
+attempt to reach later replication requests. A local real-Obsidian exercise
+reproduced the preceding Fast Fetch state but not the indefinite write. The
+evidence does not establish a milestone-specific defect, a CouchDB defect, a
+browser connection-pool defect, or a lock cycle. It does establish that the
+connectivity preflight lacks an owner which can terminate its abort-capable
+transport work.
+
+No code-level circular wait has been identified. `shareRunningResult()` shares
+a logical promise, the remote-activity counters observe work, and the global
+replication concurrency controller is entered only after the preflight. Adding
+a semaphore or another connection lock would let a stalled request retain the
+permit; it would not make that request settle.
+
+## Decision
+
+### Extend the existing connection result
+
+Commonlib will define the owned connection as the existing flat result with one
+additional operation:
+
+```typescript
+interface RemoteConnectionOpenOptions {
+    readonly signal?: AbortSignal;
+    readonly allowNativeFallback?: boolean;
+}
+
+interface OwnedCouchDBConnection<T extends object> {
+    readonly db: PouchDB.Database<T>;
+    readonly info: PouchDB.Core.DatabaseInfo;
+    close(): Promise<void>;
+}
+
+interface CouchDBReplicationConnection extends OwnedCouchDBConnection<EntryDoc> {
+    readonly syncOptionBase: PouchDB.Replication.SyncOptions;
+    readonly syncOption: PouchDB.Replication.SyncOptions;
+}
+```
+
+`RemoteService.connect()` remains the entry point. It returns
+`OwnedCouchDBConnection` directly; there is no nested resource wrapper, separate
+lease API, public connection signal, or public `abort()` operation. The
+connection and checked replication types are owned and documented by
+Commonlib. Compatibility checks enrich the same connection with replication
+options instead of creating another lifetime object.
+
+The following properties are part of the contract:
+
+- `close()` is idempotent;
+- `close()` first cancels abort-capable requests scoped to the connection, then
+  calls PouchDB's ordinary `db.close()`;
+- PouchDB retains its normal `closed` event behaviour;
+- the optional input signal cancels the same internal request scope;
+- skipping the information request retains the established placeholder in
+  `info` for source and behaviour compatibility;
+- a close failure is reported diagnostically but does not replace the primary
+  replication result; and
+- ownership of the connection does not imply ownership of a dedicated physical
+  HTTP socket.
+
+The public connection does not expose its internal signal because no caller
+needs to make a second shutdown decision. Owners either cancel through the
+input signal or finish through `close()`. This leaves one operation responsible
+for final clean-up.
+
+Replacing the existing error-string union with a typed connection-failure
+result remains desirable, but it is outside this change. Mixing that migration
+into the first implementation would enlarge the consumer and user-message
+surface without improving cancellation.
+
+### Bind cancellation at the custom fetch boundary
+
+`RemoteService.connect()` creates its internal request scope before PouchDB is
+constructed, so the initial `db.info()` request is covered. The custom PouchDB
+fetch implementation combines, without replacing, both applicable signals:
+
+- the signal supplied by PouchDB for the individual request; and
+- the signal for the owned connection, which follows its optional owner signal.
+
+The combined signal remains applicable while the response body is consumed.
+Receiving response headers is not the end of cancellation ownership.
+
+Cancellation is not a CORS failure. If the connection scope has been aborted,
+the request must not enter the diagnostic fallback from the web-compatible
+fetch path to the native request API. A bounded owner can also disable that
+fallback explicitly.
+
+The web-compatible fetch path honours `AbortSignal`. Obsidian's current native
+`requestUrl` adapter does not expose physical cancellation through
+`RequestInit.signal`. The implementation must not use `Promise.race()` to
+declare a native remote write cancelled while it may still complete. A bounded
+guarantee therefore applies only where the selected request path remains
+abort-capable.
+
+### Transfer the same connection between owners
+
+At every point, exactly one operation is responsible for calling `close()`:
+
+1. `RemoteService.connect()` owns the connection until it returns successfully;
+2. the connectivity preflight owns it while checking version and compatibility;
+3. a successful preflight transfers the same connection to the one-shot or
+   continuous replication operation; and
+4. the final replication owner closes it after replication settles or is
+   terminated.
+
+A failed factory or preflight closes the connection in its own failure path. A
+successful transfer clears the former owner's deadline before replication
+continues. Borrowing `connection.db` does not transfer close responsibility.
+
+`shareRunningResult()` owns no connection. It may share the result of an
+operation which owns one, but that operation must settle and close the
+connection before the shared entry can be released for a later attempt.
+
+## Limited Introduction
+
+The first bounded consumer is the CouchDB connectivity preflight reached from
+one-shot replication. Its boundary includes:
+
+- PouchDB construction and the initial `db.info()` request;
+- the database-version check and migration negotiation; and
+- compatibility and milestone reads and writes before replication starts.
+
+The preflight receives an internal 60-second wall-clock deadline. This is a
+last-resort safety fuse for an owner which would otherwise remain pending
+indefinitely. It is not the expected completion time, a service-level target, a
+per-request inactivity timeout, a user setting, a limit on replication
+duration, or the `useTimeouts` changes-feed setting. Tests inject a shorter
+deadline.
+
+When that deadline expires on the web-compatible path:
+
+1. the owner signal aborts the connection's request scope;
+2. the preflight closes the connection;
+3. no PouchDB replication operation is created;
+4. the shared one-shot result settles as failed; and
+5. a later trigger may create a fresh connection and attempt.
+
+On success, the deadline is cleared before the connection is transferred to
+replication, so an old timer cannot interrupt a healthy long-running transfer.
+
+The explicitly selected native Request API retains its previous unbounded
+behaviour because its host adapter cannot honour transport cancellation. The
+security-seed preparation which precedes the shared one-shot operation is also
+outside this first boundary. Fast Fetch, setup probes, maintenance commands,
+status inspection, and other direct CouchDB consumers retain their existing
+deadline and retry policies. They receive the additive `close()` contract but
+are not silently given this one-shot deadline.
+
+The first implementation does not add automatic retry. Retrying before the old
+request is known to be cancelled could duplicate remote writes or consume more
+connections without changing the failing condition.
+
+## Ownership
+
+The legacy `_ensureConnection()` method retains its raw PouchDB return type for
+source compatibility. New Commonlib paths use an internal owned-connection
+helper and do not discard the lifecycle object.
+
+Commonlib owns:
+
+- `OwnedCouchDBConnection`, `RemoteConnectionOpenOptions`, and
+  `CouchDBReplicationConnection`;
+- composition of PouchDB request and connection cancellation signals;
+- the PouchDB custom-fetch integration;
+- idempotent connection close behaviour;
+- ownership transfer within the CouchDB replicator; and
+- timeout classification at the connectivity-preflight boundary.
+
+Self-hosted LiveSync owns:
+
+- the concrete Obsidian fetch adapters and their declared capabilities;
+- user-facing logs or notices for a timed-out attempt;
+- integration of an immutable Commonlib release; and
+- real-Obsidian validation of the affected consumer path.
+
+No host may claim physical cancellation unless its injected fetch
+implementation honours the supplied signal.
+
+## Non-Goals
+
+This decision does not:
+
+- identify the exact environmental cause reported in issue 1116;
+- guarantee that a one-shot attempt succeeds;
+- special-case the milestone document or its URL;
+- impose a global connection limit or connection semaphore;
+- add an automatic retry, fallback, or remote reconciliation policy;
+- apply a deadline to ordinary replication, continuous changes feeds, Fast
+  Fetch, rebuilds, or bulk transfers;
+- change CouchDB documents, checkpoints, encryption, the security seed, or
+  compatibility Metadata;
+- make `close()` equivalent to closing a browser socket;
+- detach a potentially mutating native request and report it as cancelled; or
+- migrate every direct PouchDB borrower to the one-shot deadline policy.
+
+## Alternatives Rejected
+
+### Time out only the milestone write
+
+The observed write is where one report stopped, not an established ownership
+boundary. Another environment could stop at `db.info()`, version Metadata,
+response-body parsing, or an adjacent compatibility request.
+
+### Race the preflight without cancelling its transport
+
+This would release `shareRunningResult()` while the old request remained able
+to complete. It is especially unsafe for a remote `PUT`, because a later
+attempt could begin after the first had been reported as failed.
+
+### Add a global semaphore or lower the connection count
+
+No connection-limit failure has been demonstrated. A stalled owner would
+retain its permit indefinitely and turn an unexplained request into an explicit
+queue deadlock.
+
+### Add a separate lease wrapper
+
+A nested `{ connection: { db, close }, info }` result would make ownership
+visible, but it would duplicate the existing connection shape, force callers
+through another projection, and expose lifetime operations which have no
+consumer. Adding `close()` to the existing value preserves source compatibility
+and keeps the PouchDB handle, information snapshot, and lifetime together.
+
+### Share one global remote PouchDB handle
+
+A singleton would couple setup, maintenance, one-shot, and continuous
+lifecycles, make credential and setting changes harder to isolate, and turn one
+stalled request into a process-wide resource.
+
+## Verification
+
+The regression tests were changed before the implementation. Against the old
+flat result they demonstrated that:
+
+- an owner signal left an in-flight request pending;
+- the result had no `close()` operation capable of interrupting a body read;
+- a bounded web-compatible request could enter the native fallback; and
+- the one-shot path still depended on the discarded nested connection API.
+
+After the change, focused Commonlib tests verify that:
+
+- an owner signal settles a pending request;
+- `close()` interrupts a response body read before closing PouchDB;
+- repeated `close()` calls close the handle once;
+- an aborted or bounded request does not enter the non-abortable native adapter;
+- deadline expiry closes the same flat connection and releases the shared
+  one-shot attempt;
+- a later invocation begins after that release;
+- a successful preflight clears its deadline and transfers ownership; and
+- close failures are logged without replacing timeout or replication results.
+
+Type checking and package-boundary checks verify the Commonlib-owned
+declarations and compatibility export. Self-hosted LiveSync must then validate
+the exact packed Commonlib artefact with its focused consumer tests and an
+ordinary real-Obsidian and CouchDB smoke test. The reporter's environment
+remains the validation boundary for the original platform-specific symptom.
+
+## Consequences
+
+- A successful remote connection has one explicit close operation without a
+  parallel lease abstraction.
+- Existing `{ db, info }` consumers remain source-compatible and may adopt
+  `close()` without changing their projections.
+- One-shot connectivity can become a bounded failure on an abort-capable
+  transport instead of retaining the shared operation indefinitely.
+- Native `requestUrl` cancellation remains an acknowledged gap rather than a
+  falsely satisfied contract.
+- Other finite consumers can adopt owner signals and explicit `close()` one at
+  a time, with tests for their own side effects and retry policies.
+
+## References
+
+- [Bounded Remote Activity](2026_07_bounded_remote_activity.md)
+- [Fast Fetch Persistence and Completion Semantics](2026_08_fast_fetch_persistence_and_completion.md)
+- Commonlib PR 112, which closes finite remote PouchDB handles after their
+  logical owners settle
+- Self-hosted LiveSync issue 1116, which reports a one-shot compatibility write
+  remaining pending on one Linux and Electron environment

manifest.json

@@ -1,7 +1,7 @@
 {
     "id": "obsidian-livesync",
     "name": "Self-hosted LiveSync",
-    "version": "1.0.14",
+    "version": "1.0.15",
     "minAppVersion": "1.7.2",
     "description": "Community implementation of self-hosted livesync. Reflect your vault changes to some other devices immediately. Please make sure to disable other synchronize solutions to avoid content corruption or duplication.",
     "author": "vorotamoroz",

package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "obsidian-livesync",
-    "version": "1.0.14",
+    "version": "1.0.15",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "obsidian-livesync",
-            "version": "1.0.14",
+            "version": "1.0.15",
             "license": "MIT",
             "workspaces": [
                 "src/apps/cli",
@@ -23,7 +23,7 @@
                 "@smithy/types": "^4.14.3",
                 "@smithy/util-retry": "^4.4.5",
                 "@vrtmrz/browser-ui-kit": "0.1.0",
-                "@vrtmrz/livesync-commonlib": "0.1.15",
+                "@vrtmrz/livesync-commonlib": "0.1.16",
                 "@vrtmrz/obsidian-plugin-kit": "0.1.3",
                 "@vrtmrz/ui-interactions": "0.1.2",
                 "diff-match-patch": "^1.0.5",
@@ -4771,9 +4771,9 @@
             }
         },
         "node_modules/@vrtmrz/livesync-commonlib": {
-            "version": "0.1.15",
+            "version": "0.1.16",
-            "resolved": "https://registry.npmjs.org/@vrtmrz/livesync-commonlib/-/livesync-commonlib-0.1.15.tgz",
+            "resolved": "https://registry.npmjs.org/@vrtmrz/livesync-commonlib/-/livesync-commonlib-0.1.16.tgz",
-            "integrity": "sha512-uQxxzOdzu0MVcS6g20AxNLNj933Q3N5j/gZ2o6sem36vlsXQPKnsjGjTzrYcYAXNJ9mkR82EvC8qmKnOZvjEPg==",
+            "integrity": "sha512-vQlhLP2Qvf72zc/FedJQgOy/+Ri5zWuX+WKSD9fGaSWkBtX+nWkHx/9fgGdwkNEgighd4eCREVXfPvjcJKWX4w==",
             "license": "MIT",
             "dependencies": {
                 "@aws-sdk/client-s3": "^3.808.0",
@@ -15923,7 +15923,7 @@
         },
         "src/apps/cli": {
             "name": "self-hosted-livesync-cli",
-            "version": "1.0.14-cli",
+            "version": "1.0.15-cli",
             "dependencies": {
                 "chokidar": "^4.0.0",
                 "minimatch": "^10.2.5",
@@ -15948,7 +15948,7 @@
         },
         "src/apps/webapp": {
             "name": "livesync-webapp",
-            "version": "1.0.14-webapp",
+            "version": "1.0.15-webapp",
             "dependencies": {
                 "octagonal-wheels": "^0.1.53"
             },
@@ -15960,7 +15960,7 @@
             }
         },
         "src/apps/webpeer": {
-            "version": "1.0.14-webpeer",
+            "version": "1.0.15-webpeer",
             "dependencies": {
                 "octagonal-wheels": "^0.1.53"
             },

package.json

@@ -1,6 +1,6 @@
 {
     "name": "obsidian-livesync",
-    "version": "1.0.14",
+    "version": "1.0.15",
     "description": "Reflect your vault changes to some other devices immediately. Please make sure to disable other synchronize solutions to avoid content corruption or duplication.",
     "main": "main.js",
     "type": "module",
@@ -177,7 +177,7 @@
         "@smithy/types": "^4.14.3",
         "@smithy/util-retry": "^4.4.5",
         "@vrtmrz/browser-ui-kit": "0.1.0",
-        "@vrtmrz/livesync-commonlib": "0.1.15",
+        "@vrtmrz/livesync-commonlib": "0.1.16",
         "@vrtmrz/obsidian-plugin-kit": "0.1.3",
         "@vrtmrz/ui-interactions": "0.1.2",
         "diff-match-patch": "^1.0.5",

src/apps/cli/package.json

@@ -1,7 +1,7 @@
 {
     "name": "self-hosted-livesync-cli",
     "private": true,
-    "version": "1.0.14-cli",
+    "version": "1.0.15-cli",
     "main": "dist/index.cjs",
     "type": "module",
     "scripts": {

src/apps/webapp/package.json

@@ -1,7 +1,7 @@
 {
     "name": "livesync-webapp",
     "private": true,
-    "version": "1.0.14-webapp",
+    "version": "1.0.15-webapp",
     "type": "module",
     "description": "Browser-based Self-hosted LiveSync using FileSystem API",
     "scripts": {

src/apps/webpeer/package.json

@@ -1,7 +1,7 @@
 {
     "name": "webpeer",
     "private": true,
-    "version": "1.0.14-webpeer",
+    "version": "1.0.15-webpeer",
     "type": "module",
     "scripts": {
         "dev": "vite",

updates.md

@@ -16,6 +16,17 @@ Earlier releases remain available in the 1.0 release history, the 1.0 preview hi
 
 #### Improved
 
+- One-shot CouchDB synchronisation now releases stalled web-compatible connection checks before replication starts, so a later synchronisation can make a fresh attempt (Commonlib 0.1.16).
+    - The 60-second safeguard applies only to pre-replication checks. It does not limit ordinary synchronisation, and the **Use Internal API** path is unchanged.
+
+## 1.0.15
+
+15th August, 2026
+
+### Synchronisation and storage
+
+#### Improved
+
 - Start-up offline scanning is now faster, especially for larger Vaults using path obfuscation (Commonlib 0.1.15).
 
 ### Interface and translation

versions.json

@@ -26,5 +26,6 @@
     "1.0.11": "1.7.2",
     "1.0.12": "1.7.2",
     "1.0.13": "1.7.2",
-    "1.0.14": "1.7.2"
+    "1.0.14": "1.7.2",
+    "1.0.15": "1.7.2"
 }