CENNSO-3792: Dynamic per-server port pool: structurally safe RADIUS id reuse - #249
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The socket now connects to its server (OS-assigned source port, kernel filters replies to the peer) and keys its pending map on ReqId alone. Groundwork for the per-server port pool. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A retired socket holds its (bound) source port for reqid_reuse_timeout (the quarantine), keeps serving in-flight requests, then exits normally once cooldown elapsed AND pending is empty. Force-closed at 2x cooldown. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
no_ports now means K (concurrent active fillers per server). New opts default to 256 sockets/server cap and a 30s reqid reuse cooldown. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Replaces the blind rotating counter + static socket array with per-server pools of K connected 'filler' sockets. Each filler issues ids 0..255 then is retired (cooled+closed by the socket); a fresh one is opened on demand. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Monitors on filler/cooling sockets let the manager drop a socket from its pool when it closes (post-cooldown) or crashes, keeping the cap accounting accurate. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Address change closes all pool sockets (and demonitors) then resets; removed servers have their pools dropped. Legacy socket-array/idcounters test assertions rewritten against the pool model; no_ports_one_wraps removed (superseded by pool_rolls_and_retires). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adds rotation_uses_fresh_source_ports (across a 256-id wrap the client
sends from a fresh OS source port; no {srcport,id} pair repeats).
With the K-filler pool a RADIUS server sees the client across several
source ports, so eradius_metrics_SUITE sums the server-side per-nas_ip
request/reply counters instead of expecting a single label-set.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- socket_sup: restart => temporary. Pool sockets are manager-managed (opened on demand, monitored, reclaimed on exit); auto-restart would orphan a socket the manager never learns about. - Refresh the eradius_client_mngr 'Socket pool' moduledoc for the per-server dynamic pool (no_ports=K, reqid_reuse_timeout, max_ports_per_server). - Add max_ports_per_server/reqid_reuse_timeout to client_config() type; tighten no_ports to pos_integer(). - Remove now-unused test-only get_socket_count/1. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The active filler list is a FIFO round-robin (take head, re-enqueue at tail; new fillers appended; retired head dropped). Model it with the queue module: queue:out/in for the rotation, queue:filter for by-pid removal on DOWN. No behaviour change. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A filler's pid is unique, so removing it from the active queue on DOWN is a single-element delete; queue:delete_with expresses that and short-circuits instead of rebuilding the whole queue like queue:filter. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Summary
Replaces the eradius client's blind rotating Identifier allocator (
next_port_and_req_id/3+ static socket array) with a dynamic per-server pool of connected UDP sockets. Each socket is dedicated +gen_udp:connected to one server (OS-assigned source port; kernel filters replies to the peer), issues request ids0..255exactly once, then is retired: held open forreqid_reuse_timeout(the bound source port is the quarantine), drained, and closed.no_ports, default 10), round-robin; rolls to a fresh socket every 256 ids.max_ports_per_server(default 256) →{error, no_ports}backpressure instead of a silent Identifier collision.reconfigurecloses/rebuilds pools and drops removed servers' pools; pool sockets aretemporary(manager-managed).Why
Under a slow RADIUS server the old allocator re-issued live
{port, id}pairs, causing the client hang (mode A, mitigated in #248), premature reuse vs the server's duplicate-detection window (mode B), and delayed-reply misrouting (mode C). Rotating the source port makes reuse structurally safe: a reused id always lands on a fresh(client IP, port)key, which the server sees as a distinct client. Builds on #248 (the bounded call timeout guarantees in-flight drains within the cooldown).Behavioral change to note
With K active fillers round-robined, a single RADIUS server now sees the client across up to K source ports concurrently (the old code pinned a peer to one source port, rotating every 256). This is intended (throughput / mailbox spread) and safe.
eradius_metrics_SUITEwas updated to sum the server-side per-nas_ipcounters accordingly.Test plan
{error, no_ports};'DOWN'reclaims cooling slots; reconfigure resets pools.{srcport, id}pair repeats within the cooldown.rebar3 ctgreen on OTP 28.3 (153 tests);rebar3 fmtclean.Follow-ups (not in this PR)
active/cooling/totalgauges +no_ports/open/close counters viametrics_callback. This PR ships a minimalno_ports_rejectionsstate counter + warning log; full metric wiring is deferred.eradius_client:send_request_loopmatches{error, close}but the socket returns{error, closed}, so a closed socket surfaces as a generic error rather thansocket_down. Predates this work; worth a small follow-up.Design spec:
docs/superpowers/specs/2026-06-04-eradius-dynamic-port-pool-design.md🤖 Generated with Claude Code