https://github.com/iovisor/bcc script to log connected blocks via USDT probes (see https://github.com/bitcoin/bitcoin/pull/19866). Can be used with https://github.com/0xB10C/bitcoin/tree/usdt-probes%2Bconnected_block

blockconnected-bcc.py

from __future__ import print_function
from bcc import BPF, USDT
import sys
from datetime import datetime

if len(sys.argv) < 2:
    print("USAGE:", sys.argv[0], "path/to/bitcoind")
    exit()
path = sys.argv[1]
debug = False

bpf_text = """
#include <uapi/linux/ptrace.h>

struct connect_block_t
{
    u32 height;
    u8 hash[32];
};

BPF_PERF_OUTPUT(connected_blocks);

int do_trace(struct pt_regs *ctx) {
    struct connect_block_t cb = {};
    bpf_usdt_readarg(1, ctx, &cb.height);
    bpf_usdt_readarg_p(2, ctx, &cb.hash, sizeof(cb.hash));
    connected_blocks.perf_submit(ctx, &cb, sizeof(cb));
    return 0;
};
"""

u = USDT(path=str(path))
u.enable_probe(probe="connect_block", fn_name="do_trace")

if debug:
    print(u.get_text())

b = BPF(text=bpf_text, usdt_contexts=[u])

def print_connected_blocks(cpu, data, size):
    event = b["connected_blocks"].event(data)
    height = event.height
    hash_bytes = bytearray(event.hash)
    hash_bytes.reverse()
    hash = hash_bytes.hex()
    print(datetime.now(), "height:", height, "hash:", hash)

b["connected_blocks"].open_perf_buffer(print_connected_blocks)

while 1:
    try:
        b.perf_buffer_poll()
    except KeyboardInterrupt:
        exit()

testnet-output.txt

2020-12-31 12:05:40.634456 height: 1901575 hash: 0000000000000012e5bad3eb72856bc8cee92b4da47c7d0ee49db1463345a1f8
2020-12-31 12:10:11.215210 height: 1901576 hash: 00000000000000107e1cef35dc0557a49f5642b0b9b289ebc1cee454797ed1c3
2020-12-31 12:14:00.349253 height: 1901577 hash: 0000000000000004c7abf45ba560c28e7bfa39c19e28284f8a640e33ee4069d1
2020-12-31 12:17:02.398484 height: 1901578 hash: 00000000000000027b2f88e8cc4e4b0f8a7ad9d0142f282d272827201875e7c4
2020-12-31 12:17:17.796756 height: 1901579 hash: 000000000000001a64e5d01f08c3183165fa2d8225d881081c4b80bb1ffba5b8
2020-12-31 12:18:40.852506 height: 1901580 hash: 0000000000000010da1398d31de9d46eac62caf2a2c4ae1f7b91041ba612a0ae