Mempool service not starting on 0.4.0

Services Support
1

Hi,
I just upgraded from 0.3.5. to 0.4.0 Beta 1 and then beta 2. Process was quite smooth and after every services was upgraded it works flawless. Im on a DIY-VM on Proxmox.

However Mempool does not start. I use electrs and I get the following log lines:

2026-04-05T09:54:20+02:00  Apr 5 07:54:20 [123] NOTICE: Starting Mempool Server... (32fadb4)
2026-04-05T09:54:20+02:00  2026-04-05 7:54:20 20 [Warning] Access denied for user 'mempool'@'127.0.0.1' (using password: YES)
2026-04-05T09:54:20+02:00  Apr 5 07:54:20 [123] ERR: Could not connect to database: Access denied for user 'mempool'@'127.0.0.1' (using password: YES)

Those are repeating.

I tried already to ā€œrebuildā€ the Mempool service, and completely uninstalling and reinstall it, that does not change the result.
Any ideas where else to look?

1 Like
2

Thanks, weā€™ll look into it.

3

Wait, you said you completely uninstalled Mempool, then installed it completely fresh, and got this error again?

4

yes. completely removed Mempool app via uninstall button, then installed again.

5

Can you confirm the exact version of StartOS and the exact version of Mempool?

6

Mempool version 3.2.1:9
StartOS is 0.4.0-beta.2
electrs is 0.11.1:1

After checking electrs logs i can see a matching pattern which is also repeating over and over:

2026-04-05T16:45:54+02:00  [2026-04-05T14:45:54.908Z
 WARN  electrs::server] 615: failed to shutdown TCP receiving Transport 
endpoint is not connected (os error 107)
2026-04-05T16:45:54+02:00  [2026-04-05T14:45:54.908Z WARN  electrs::thread] recv_loop thread failed: 615: recv failed
2026-04-05T16:45:54+02:00  [2026-04-05T14:45:54.908Z WARN  electrs::thread] because: Connection reset by peer (os error 104)

Electrs is working with my Specter wallet.

7

Could you please download the full Mempool logs (it outputs a html file) and email that to me at stu@start9.com ? Thank you.

8

I have a similar error with a fresh install of StartOS (not a migration from 3.5.1).

-StartOS is 0.4.0-beta.5

  • Fulcrum is 2.1.0:7
  • Mempool 3.2.1:9. I have uninstalled and reinstalled multiple times now, am downgrading to 3.2.1:8 to see if that works.

The below repeats over and over in the mempool logs. I can ssh into the server & can download via CURL the ā€œpools-v2.jsonā€ file no problem, so it doesnt appear to be networking issue.

2026-04-17T10:22:02+10:00 Version: ā€˜10.4.32-MariaDB-1:10.4.32+maria~ubu2004ā€™ socket: ā€˜/var/run/mysqld/mysqld.sockā€™ port: 3306 mariadb.org binary distribution
2026-04-17T10:22:03+10:00 daemon sync waiting on api
2026-04-17T10:22:03+10:00 Launching apiā€¦
2026-04-17T10:22:04+10:00 daemon sync waiting on api

2026-04-17T10:22:06+10:00 Apr 17 00:22:06 [2] NOTICE: Starting Mempool Serverā€¦ (32fadb4)
2026-04-17T10:22:06+10:00 Apr 17 00:22:06 [2] INFO: Database connection established.
2026-04-17T10:22:06+10:00 Apr 17 00:22:06 [2] INFO: Connected to Electrum Server at fulcrum.startos:50001 ([ā€œFulcrum 2.1.0ā€,ā€œ1.4ā€])

2026-04-17T10:22:07+10:00 Apr 17 00:22:07 [2] INFO: [PoolsUpdater] Downloading pools-v2.json for the first time from https://raw.githubusercontent.com/mempool/mining-pools/master/pools-v2.json over clearnet

2026-04-17T10:22:10+10:00 Apr 17 00:22:10 [2] ERR: [PoolsUpdater] Could not connect to Github. Reason:
2026-04-17T10:22:10+10:00 Apr 17 00:22:10 [2] ERR: Failed to retreive pools-v2.json sha, cannot run block indexing. Please make sure youā€™ve set valid urls in your mempool-config.json::MEMPOOL::POOLS_JSON_URL and mempool-config.json::MEMPOOL::POOLS_JSON_TREE_UR, aborting now

9

Thats not a similar error, your instance can connect to MariaDB.

Instead it looks like it cannot connect to https://raw.githubusercontent.com/mempool/mining-pools/master/pools-v2.json
Make sure that this is not blocked by pihole etc. and your DNS resolving is working properly