Seeding nodes lease first, connect for the lease, close when idle

A failed NNTP login gives the range back uncounted (no attempt used), and a
node with nothing to lease holds no connection. Replaces log-in-before-lease,
which kept idle connections and logged in again every minute while idle.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

commands/SeedNode.ts

@@ -84,33 +84,40 @@ export default class SeedNode extends BaseCommand {
 
   private async work(api: SeedApi, worker: number) {
     const log = (message: string) => this.logger.info(`[${worker}] ${message}`)
-    // Logged in before leasing, so a node that can't reach its news server takes no range
-    // (each lease counts as an attempt; a range is set aside after five). Kept across ranges.
+    // The NNTP connection is opened for a lease and kept while leases keep coming; with
+    // nothing to lease it's closed, so an idle node holds no connections.
     let client: XoverClient | undefined
-    let idleSince = Date.now()
     try {
       while (!this.stopping) {
-        // A news server may drop a connection that sat idle (nothing to lease): log in afresh.
-        if (client && Date.now() - idleSince > 2 * 60_000) {
-          client.close()
+        const lease = await this.lease(api, log)
+        if (!lease) {
+          client?.close()
           client = undefined
+          if (this.once) return
+          await this.pause(60_000)
+          continue
         }
         if (!client) {
           try {
             client = await this.connect()
           } catch (error: any) {
+            // Never started: the lease doesn't count as one of the range's attempts.
             const ipLimit = /simultaneous IP/i.test(error.message)
             log(`NNTP login failed: ${error.message}; trying again in ${ipLimit ? 5 : 1} min`)
+            await api
+              .post(`/api/v1/seed/ranges/${lease.id}/release`, {
+                error: `NNTP login: ${error.message}`,
+                uncounted: true,
+              })
+              .catch(() => {})
             await this.pause(ipLimit ? 300_000 : 60_000)
             continue
           }
         }
-        const outcome = await this.range(api, client, log)
-        if (outcome === 'replace') {
+        if (!(await this.workRange(api, client, lease, log))) {
           client.close()
           client = undefined
         }
-        if (outcome !== 'idle') idleSince = Date.now()
       }
     } finally {
       client?.close()
@@ -130,30 +137,24 @@ export default class SeedNode extends BaseCommand {
     })
   }
 
-  /**
-   * Leases and works one range: 'done', 'idle' (nothing leased; the connection
-   * wasn't used), or 'replace' (the connection may be in an odd state).
-   */
-  private async range(
-    api: SeedApi,
-    client: XoverClient,
-    log: (message: string) => void
-  ): Promise<'done' | 'idle' | 'replace'> {
-    let lease: Lease | null
+  /** The next range, or null when there is none (or the API can't be reached; logged). */
+  private async lease(api: SeedApi, log: (message: string) => void): Promise<Lease | null> {
     try {
-      lease = ((await api.post('/api/v1/seed/lease')) as { range: Lease } | null)?.range ?? null
+      return ((await api.post('/api/v1/seed/lease')) as { range: Lease } | null)?.range ?? null
     } catch (error: any) {
       if (error instanceof Unauthorized) throw error
       log(`Lease failed: ${error.message}`)
-      await this.pause(60_000)
-      return 'idle'
-    }
-    if (!lease) {
-      if (this.once) this.stopping = true
-      else await this.pause(60_000)
-      return 'idle'
+      return null
     }
+  }
 
+  /** Works one leased range; false when the NNTP connection should be replaced. */
+  private async workRange(
+    api: SeedApi,
+    client: XoverClient,
+    lease: Lease,
+    log: (message: string) => void
+  ): Promise<boolean> {
     log(`${lease.group} ${lease.start}–${lease.end}`)
     const started = Date.now()
     let headers = 0
@@ -178,7 +179,7 @@ export default class SeedNode extends BaseCommand {
           if (this.stopping) throw new Stopping()
           while (posting.size >= 2) await Promise.race(posting)
           const post = chain.then(async () => {
-            await api.post(`/api/v1/seed/ranges/${lease!.id}/batches`, batch)
+            await api.post(`/api/v1/seed/ranges/${lease.id}/batches`, batch)
             headers += batch.headers
           })
           chain = post
@@ -193,13 +194,13 @@ export default class SeedNode extends BaseCommand {
       log(
         `done: ${headers.toLocaleString('en')} headers in ${seconds.toFixed(0)} s (${Math.round(headers / seconds).toLocaleString('en')}/s)`
       )
-      return 'done'
+      return true
     } catch (error: any) {
       if (error instanceof Unauthorized) throw error
       // An XOVER may still be in flight: the connection is replaced either way.
       if (error instanceof LeaseLost) {
         log(`Range ${lease.id} passed to another node; dropping it.`)
-        return 'replace'
+        return false
       }
       const reason = error instanceof Stopping ? 'node stopping' : error.message
       if (!(error instanceof Stopping)) log(`Range ${lease.id} failed: ${reason}`)
@@ -207,7 +208,7 @@ export default class SeedNode extends BaseCommand {
       await chain.catch(() => {})
       await api.post(`/api/v1/seed/ranges/${lease.id}/release`, { error: reason }).catch(() => {})
       if (!this.stopping) await this.pause(30_000)
-      return 'replace'
+      return false
     }
   }