Ocean Pool DATUM Template Error

Verify Ocean's DATUM service is up. Open https://status.ocean.xyz in a browser and confirm green status on the DATUM endpoint. Cross-check the @OCEANMiningPool feed and the Ocean Discord #status channel. If Ocean's DATUM is in degraded or maintenance state, the entire fleet of operator gateways will return template errors — wait it out, or fail miners over to a non-DATUM Ocean endpoint (`mine.ocean.xyz:3334`) for the duration. This single check resolves about 15% of DATUM tickets at D-Central's bench.

Confirm the pool URL, port, and worker format on the miner. Ocean's DATUM endpoint is `datum.ocean.xyz:3334` (TCP, plain stratum) for the public gateway, or `<your-gateway-ip>:3334` if you're running your own. The worker must be a native SegWit `bc1q...` Taproot-compatible Bitcoin address — Ocean enforces a Taproot-mandate payout policy and will silently refuse templates to legacy `1...` / `3...` addresses. No Lightning address, no exchange address, no rig name only. Power-cycle the miner for 30 seconds after saving config — warm reboots don't always clear stuck stratum state.

From a laptop on the same LAN, run `nslookup datum.ocean.xyz` and `nc -vz datum.ocean.xyz 3334`. DNS should resolve quickly to a public IP and the TCP test should connect within 2 seconds. If DNS is slow or fails, override the router's resolver to `1.1.1.1` (Cloudflare) and `8.8.8.8` (Google), reboot the router, retry. Canadian residential ISPs (Bell, Rogers, Vidéotron, Cogeco, Shaw) occasionally produce flaky DNS for newer mining hostnames at their default resolvers — not blocked, just slow enough to trip the miner's stratum-handshake timeout.

Fail-over test against a non-DATUM Ocean endpoint. Re-point the miner at `mine.ocean.xyz:3334` (Ocean's classic non-DATUM stratum) keeping the same `bc1q...` worker address. Save, power-cycle 30 seconds. If shares start flowing immediately at this endpoint, Ocean's network and your miner are both healthy — the failure is isolated to DATUM. If shares still don't flow, the problem is upstream of the pool (DNS, NAT, ISP, firmware) and you need Tier 2 isolation.

If you are running your own DATUM Gateway: check the gateway daemon process. SSH to the host running `datum_gateway`. Run `systemctl status datum-gateway` (or your equivalent service unit). Confirm the binary is alive, not crash-looping, and listening on `0.0.0.0:3334` (use `ss -tlnp | grep 3334`). Tail the gateway log: `journalctl -u datum-gateway -f --since '15 min ago'`. Look for `template construction failed`, `getblocktemplate timeout`, or `connection to bitcoind failed`. Each error string maps to a specific Tier 3 fix below.

Verify Bitcoin Core node sync and RPC reachability. Run `bitcoin-cli getblockchaininfo` and confirm `verificationprogress` is `1.0` (or at least `0.9999`+). A node still in IBD cannot serve `getblocktemplate` cleanly — DATUM Gateway will log template errors continuously until the node is fully synced. On a fresh Core install on consumer hardware, full IBD takes 1-3 days. Run `bitcoin-cli getmempoolinfo` to confirm the mempool is populated. Run `bitcoin-cli -rpcwait getnetworkinfo` to confirm RPC connectivity from the gateway host.

Check the Bitcoin Core RPC config used by `datum_gateway`. Open the gateway's config file (commonly `/etc/datum-gateway/datum.conf` or per the install method's docs at github.com/ocean-mining/datum). Confirm `rpcuser`, `rpcpassword` (or `rpccookiefile`), `rpchost`, and `rpcport` match what's in `bitcoin.conf`. Test with `curl --user user:pass --data-binary '{"jsonrpc":"1.0","method":"getblocktemplate","params":[{"rules":["segwit"]}]}' -H 'content-type: text/plain;' http://127.0.0.1:8332/`. If you don't get a JSON template back in under 2 seconds, the RPC path is broken — fix that before troubleshooting anything else.

Confirm `bitcoind` has the indexes DATUM Gateway expects. At minimum, `bitcoin.conf` should include `server=1`, `rpcallowip=127.0.0.1` (or the gateway's IP), `rpcbind=0.0.0.0` (only if remote), `txindex=1` if you want full mempool template flexibility, and `blockfilterindex=1`. Restart `bitcoind` after changes — the node will rebuild indexes on next start (10 minutes to several hours depending on hardware). Re-test `getblocktemplate` from Step 7 once the indexes are ready.

Open the firewall path between miner and DATUM Gateway. If `datum_gateway` runs on a separate box on your LAN, confirm the miner's subnet can reach `<gateway-ip>:3334`. On a typical home router behind CGNAT or a strict firewall, you may need a port-forward or LAN-rule. If the gateway is exposed to the public internet (some operators do this), expect more aggressive abuse traffic — bind it to a Tor onion service for sanity. Sample iptables rule on Linux: `iptables -A INPUT -p tcp --dport 3334 -s 192.168.1.0/24 -j ACCEPT`. Restart, retest from the miner.

On Bitaxe (any model — Supra, Ultra, Hex, Gamma, GT, Max), update AxeOS / ESP-Miner to the latest stable release at github.com/skot/ESP-Miner. Some older AxeOS builds had stratum-handshake bugs against version-rolling pools that present as template errors. Flash via the Web UI > System > Update OTA path. For ESP32-based NerdMiner / NerdAxe / NerdQAxe / NerdNOS hardware, follow the firmware's documented update procedure — most use a USB-C OTA flash. D-Central pioneered the Bitaxe Mesh Stand and the Bitaxe Hex heatsink; if you're a customer, contact our support for the firmware version we ship out of the box.

On Antminer hardware, flash DCENT_OS — D-Central's open-source Antminer firmware — for clean Ocean DATUM stratum support, per-chip diagnostics, and modern stratum-extension handling. Bitmain's stock stratum client is conservative and does not always tolerate version-rolling extensions Ocean's DATUM endpoint negotiates. DCENT_OS ships a stratum stack rebuilt from the ground up for the open-source community. Alternatives: Braiins OS+, LuxOS, Vnish — all four expose better stratum diagnostics than stock. Get DCENT_OS at https://d-central.tech/dcent-os/ — built by Mining Hackers, for Mining Hackers, source on GitHub at https://github.com/DCentralTech/DCENT_OS.

Capture a packet trace of the stratum handshake. From the miner's network or a tap point, run `tcpdump -i any -w /tmp/datum.pcap host datum.ocean.xyz and port 3334` for 2 minutes while the miner attempts to connect. Open the pcap in Wireshark, filter on `tcp.port == 3334`, and look for: TCP SYN → SYN-ACK → ACK (network OK), then JSON `mining.subscribe` → `mining.notify` (stratum OK), or `mining.subscribe` with no response (pool-side issue), or no SYN-ACK (network filtering). This isolates client vs network vs pool in 5 minutes flat.

Restart `datum_gateway` cleanly after Bitcoin Core is healthy. Some gateway builds cache an unhealthy upstream RPC connection on first start — the only way out is a clean restart once the node is at tip. `systemctl restart datum-gateway` on a systemd host, or relaunch the binary in your terminal multiplexer. Tail the log on restart: the first 60 seconds should emit `connecting to bitcoind`, `RPC handshake OK`, and `stratum listening on 0.0.0.0:3334`. If any of those don't appear, the gateway has a config or network problem — re-walk Steps 7-9.

Verify the worker payout address on Ocean's web dashboard. Log in to ocean.xyz with the `bc1q...` address you configured on the miner. Confirm the address shows up under your account, has the correct Taproot-compatible format, and that the worker name (the part after the period in `bc1q...XYZ.workername`) matches what the miner is sending. Mismatched workers can authenticate (Ocean is permissive on workername) but can produce confusing template-acceptance behaviour — clean this up before assuming it's a node-side issue.

Run a 30-minute soak test. After applying the fix, leave the miner alone for 30 minutes. Check ocean.xyz dashboard at the 5-, 15-, and 30-minute marks. Effective hashrate should rise from 0 to a value within ±15% of the miner's local H/s (variance window is wider than other pools because Ocean's payout is per-block per-miner not per-share averaged). If hashrate is stable and shares are landing, you're fixed. If it's flapping, return to Step 12 and capture a longer trace — a flapping symptom usually means upstream NAT, ISP backbone routing, or DATUM Gateway memory leak (rare, but documented in the github.com/ocean-mining/datum issues).

If you are running your own DATUM Gateway, harden it for production. Bind to localhost-only and front it with Tor for inbound miner connections (datum.conf supports a `listener_tor` config block — see Ocean's official docs). Set up Prometheus / textfile exporter on `datum_gateway` log lines so you alert on `template construction failed` rate-of-change. Run the gateway as a non-root systemd unit. Keep `bitcoind` on a separate user, separate disk, and back up `wallet.dat` (if used) off-host. Sovereign template construction is a privilege; harden accordingly.

Stop DIY and engage D-Central when: (a) DATUM Gateway log shows `template construction failed` at high rate against a fully synced node and you've ruled out RPC, txindex, and firewall, (b) you want the Mining Hackers to deploy a turnkey DATUM Gateway + Bitcoin Core stack on dedicated hardware, (c) Antminer hardware needs DCENT_OS deployed with a known-good Ocean DATUM stratum config, (d) Bitaxe / NerdMiner firmware is suspect and you want a clean flash + Ocean DATUM bring-up, (e) you're standing up Ocean DATUM as part of a hosting/colo deployment in Canada, or (f) physical damage on the miner is suspected. Book at https://d-central.tech/services/asic-repair/ — or hit Discord for the open-source firmware crew.