Strong degrading performance during continuous use of Electrs

[MvdS74]

I'm running Electrs + Bitcoin Core on a dedicated Debian machine (Xeon E3-1225V6 4c/4t, 64GB DDR4, 2TB m.2 NVME SSD).

The startup information given by Electrs is: Mar 06 10:35:11 Hephaistos electrs[567]: Starting electrs 0.10.9 on x86_64 linux with Config { network: Bitcoin, db_path: "/var/lib/electrs/db/bitcoin", db_log_dir: None, db_parallelism: 4, daemon_auth: CookieFile("/var/lib/bitcoin/.bitcoin/.cookie"), daemon_rpc_addr: 127.0.0.1:8332, daemon_p2p_addr: 127.0.0.1:8333, electrum_rpc_addr: 127.0.0.1:50001, monitoring_addr: 127.0.0.1:4224, wait_duration: 10s, jsonrpc_timeout: 15s, index_batch_size: 10, index_lookup_limit: None, reindex_last_blocks: 0, auto_reindex: true, ignore_mempool: false, sync_once: false, skip_block_download_wait: false, disable_electrum_rpc: false, server_banner: "Welcome to electrs 0.10.9 (Electrum Rust Server)!", signet_magic: f9beb4d9 }

After starting up, I see that Electrs is capable of handling around 250 calls per seconds (coming from multiple clients/threads) and that seems to be degrading almost immediately until it stabilizes at around 70-80 calls per second. CPU utilization is stable around 30-35%, ram utilization around 10%, SSD write around 0-5 IOPS, read around 50-100 IOPS.

This information shows me that the system is not close to being maxed out, so I think that Electrs is struggling.

Can I test this somehow? Can I do optimalisations in the config to get Electrs to perform better?