[elements node] out of memory fatal error

[agyx]

Describe the issue

Shortly after start with elementsd -daemon, the daemon exits with out of memory error:

2020-11-27T17:56:12Z Elements Core version elements-0.18.1.9 (release build)
2020-11-27T17:56:12Z Validating signatures for all blocks.
2020-11-27T17:56:12Z Setting nMinimumChainWork=0000000000000000000000000000000000000000000000000000000000000000                                                                                            
2020-11-27T17:56:12Z Using the 'sse4(1way),sse41(4way)' SHA256 implementation
2020-11-27T17:56:12Z Using RdRand as an additional entropy source
2020-11-27T17:56:12Z Default data directory /home/bertrand/.elements
2020-11-27T17:56:12Z Using data directory /home/bertrand/.elements/liquidv1
2020-11-27T17:56:12Z Config file: /home/bertrand/.elements/elements.conf
2020-11-27T17:56:12Z Using at most 125 automatic connections (1024 file descriptors available)
2020-11-27T17:56:12Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements                                                                                                 
2020-11-27T17:56:12Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements                                                                                          
2020-11-27T17:56:12Z Using 32 MiB out of 32 requested for rangeproof cache, able to store 1048576 elements                                                                                                 
2020-11-27T17:56:13Z Using 32 MiB out of 32 requested for surjectionproof cache, able to store 1048576 elements                                                                                            
2020-11-27T17:56:13Z Using 2 threads for script verification
2020-11-27T17:56:13Z scheduler thread start
2020-11-27T17:56:13Z HTTP: creating work queue of depth 16
2020-11-27T17:56:13Z No rpcpassword set - using random cookie authentication.
2020-11-27T17:56:13Z Generated RPC authentication cookie /home/bertrand/.elements/liquidv1/.cookie
2020-11-27T17:56:13Z HTTP: starting 4 worker threads
2020-11-27T17:56:13Z Using wallet directory /home/bertrand/.elements/liquidv1/wallets
2020-11-27T17:56:13Z init message: Verifying wallet(s)...
2020-11-27T17:56:13Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2020-11-27T17:56:13Z Using wallet /home/bertrand/.elements/liquidv1/wallets
2020-11-27T17:56:13Z BerkeleyEnvironment::Open: LogDir=/home/bertrand/.elements/liquidv1/wallets/database ErrorFile=/home/bertrand/.elements/liquidv1/wallets/db.log                                       
2020-11-27T17:56:13Z init message: Loading banlist...
2020-11-27T17:56:13Z Cache configuration:
2020-11-27T17:56:13Z * Using 2.0 MiB for block index database
2020-11-27T17:56:13Z * Using 8.0 MiB for chain state database
2020-11-27T17:56:13Z * Using 440.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space)                                                                                               
2020-11-27T17:56:13Z init message: Loading block index...
2020-11-27T17:56:13Z Opening LevelDB in /home/bertrand/.elements/liquidv1/blocks/index
2020-11-27T17:56:13Z Opened LevelDB successfully
2020-11-27T17:56:13Z Using obfuscation key for /home/bertrand/.elements/liquidv1/blocks/index: 0000000000000000                                                                                            
2020-11-27T17:57:40Z LoadBlockIndexDB: last block file = 11
2020-11-27T17:57:40Z LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=27514, size=121926917, heights=397644...425164, time=2019-07-20...2019-08-10)                                           
2020-11-27T17:57:40Z Checking all blk files are present...
2020-11-27T17:57:40Z Opening LevelDB in /home/bertrand/.elements/liquidv1/chainstate
2020-11-27T17:57:40Z Opened LevelDB successfully
2020-11-27T17:57:40Z Using obfuscation key for /home/bertrand/.elements/liquidv1/chainstate: c6f9a82d7855925b                                                                                              
2020-11-27T17:57:40Z Upgrading utxo-set database...
2020-11-27T17:57:40Z [0%]...[DONE].
2020-11-27T17:57:40Z Loaded best chain: hashBestChain=b72e1c78a9eeb2176e65f0cbfe68ba7e0ad7b9ec4792ab514f93dc07d5c3a0e6 height=425158 date=2019-08-10T14:50:59Z progress=0.384                              
2020-11-27T17:57:40Z init message: Rewinding blocks...
2020-11-27T17:57:53Z Error: Out of memory. Terminating.

What behavior did you expect?

No error

What was the actual behavior (provide screenshots if the issue is GUI-related)?

The daemon exited after about 2 minutes.

How reliably can you reproduce the issue, what are the steps to do so?

• start a node from scratch
• after 100000 blocks downloaded, stop it with cli
• try to restart the node, it won't

What version of Bitcoin Core+Elements are you using, where did you get it (website, self-compiled, etc)?

bitcoin 0.20.1 (archive from website)
elements 0.18.1.9 (archive from github)

What type of machine are you observing the error on (OS/CPU and disk type)?

Server Informations:

Item	Description
CPU	Intel Atom C2350 1.70GHz
RAM	4GB
Disk	SATA 500GB
Bandwidth	1Gbps
OS	Debian buster

For the GUI-related issue on Linux provide names and versions of a distro, a desktop environment and a graphical shell (if relevant).

n/a

Any extra information that might be useful in the debugging process.

bitcoind is working fine in this environment

This is normally the contents of a debug.log or config.log file. Raw text or a link to a pastebin type site are preferred.

debug.log: See above
elements.conf:

server=1

mainchainrpcuser=********
mainchainrpcpassword=********