OceanBase 4.x改装：另一种全链路追踪的尝试

#include <sys/sdt.h>

int main() {
    DTRACE_PROBE(MyProvider, myprobe);
    return 0;
}

mkdir -p /home/frank/data/clog
mkdir -p /home/frank/data/slog/server
mkdir -p /home/frank/data/sstable

./observer -r 127.0.0.1:2882:2881 -p 2881 -P 2882 -z zone1 -n obcluster -c 1 -d /home/frank/data -i lo -l INFO -o ob_trx_idle_timeout=120,__min_full_resource_pool_memory=2147483648,enable_syslog_recycle=True,enable_syslog_wf=True,max_syslog_file_count=4,memory_limit=6G,datafile_size=20G,log_disk_size=24G,system_memory=1G,cpu_count=16 -l ERROR

obclient -h 127.0.0.1 -P 2881 -uroot

Consolidate compiler generated dependencies of target obcdc_static
Consolidate compiler generated dependencies of target obcdc
[ 97%] Built target obcdc_static
[ 97%] Linking CXX executable observer
[ 97%] Linking CXX shared library libobcdc.so
ld.lld: error: undefined symbol: pthread_mutexattr_setrobust_np
>>> referenced by proc_mutex.c
>>>               proc_mutex.o:(proc_mutex_pthread_create) in archive ../../../deps/3rd/usr/local/oceanbase/deps/devel/lib/libapr-1.a
>>> did you mean: pthread_mutexattr_setrobust_np@GLIBC_2.4
>>> defined in: /lib/x86_64-linux-gnu/libc.so.6

ld.lld: error: undefined symbol: pthread_mutex_consistent_np
>>> referenced by proc_mutex.c
>>>               proc_mutex.o:(proc_mutex_pthread_acquire) in archive ../../../deps/3rd/usr/local/oceanbase/deps/devel/lib/libapr-1.a
>>> referenced by proc_mutex.c
>>>               proc_mutex.o:(proc_mutex_pthread_tryacquire) in archive ../../../deps/3rd/usr/local/oceanbase/deps/devel/lib/libapr-1.a
>>> did you mean: pthread_mutex_consistent_np@GLIBC_2.4
>>> defined in: /lib/x86_64-linux-gnu/libc.so.6

ld.lld: error: undefined symbol: sys_siglist
>>> referenced by signals.c
>>>               signals.o:(apr_signal_description_get) in archive ../../../deps/3rd/usr/local/oceanbase/deps/devel/lib/libapr-1.a

ld.lld: error: undefined symbol: pthread_yield
>>> referenced by thread.c
>>>               thread.o:(apr_thread_yield) in archive ../../../deps/3rd/usr/local/oceanbase/deps/devel/lib/libapr-1.a
clang-11: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [src/observer/CMakeFiles/observer.dir/build.make:154: src/observer/observer] Error 1
make[1]: *** [CMakeFiles/Makefile2:10163: src/observer/CMakeFiles/observer.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 97%] Built target obcdc
make: *** [Makefile:166: all] Error 2

# 编译内核
apt-get install flex bison libssl-dev libelf-dev dwarves
git clone https://github.com/microsoft/WSL2-Linux-Kernel.git
cd WSL2-Linux-Kernel
KERNEL_VERSION=$(uname -r | cut -d '-' -f 1)
git checkout linux-msft-wsl-$KERNEL_VERSION

cp Microsoft/config-wsl .config
make oldconfig && make prepare
make scripts
make modules
sudo make modules_install

sudo mv /lib/modules/$KERNEL_VERSION-microsoft-standard-WSL2+/ /lib/modules/$KERNEL_VERSION-microsoft-standard-WSL2

CONFIG_BPF=y
CONFIG_BPF_SYSCALL=y
# [optional, for tc filters]
CONFIG_NET_CLS_BPF=m
# [optional, for tc actions]
CONFIG_NET_ACT_BPF=m
CONFIG_BPF_JIT=y
# [for Linux kernel versions 4.1 through 4.6]
CONFIG_HAVE_BPF_JIT=y
# [for Linux kernel versions 4.7 and later]
CONFIG_HAVE_EBPF_JIT=y
# [optional, for kprobes]
CONFIG_BPF_EVENTS=y
# Need kernel headers through /sys/kernel/kheaders.tar.xz
CONFIG_IKHEADERS=y

sudo apt install liblzma-dev
sudo apt install libclang-14-dev
git clone https://github.com/iovisor/bcc.git
mkdir bcc/build; cd bcc/build
cmake ..
make
sudo make install

cmake -DPYTHON_CMD=python3 .. # build python3 binding
pushd src/python/
make
sudo make install
popd

$ tplist-bpfcc -l /home/frank/github/oceanbase/build_debug/src/observer/observer
# 注意：要使用绝对路径

$ readelf -n observer

#!/usr/bin/python

from __future__ import print_function
from bcc import BPF, USDT
from bcc.utils import printb
import sys

if len(sys.argv) < 2:
    print("USAGE: OceanBase_latency PID")
    exit()
pid = sys.argv[1]
debug = 0

# load BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
int do_trace(struct pt_regs *ctx) {
    uint64_t addr;
    char query[128];
    bpf_usdt_readarg(1, ctx, &addr);
    bpf_probe_read_user(&query, sizeof(query), (void *)addr);
    bpf_trace_printk("%s\\n", query);
    return 0;
};
"""

# enable USDT probe from given PID
u = USDT(pid=int(pid))
u.enable_probe(probe="stmt_query", fn_name="do_trace")
if debug:
    print(u.get_text())
    print(bpf_text)

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

# header
print("%-18s %-16s %-6s %-6s %s" % ("TIME(s)", "COMM", "PID", "CPU", "QUERY"))

# format output
while 1:
    try:
        (task, pid, cpu, flags, ts, msg) = b.trace_fields()
    except ValueError:
        print("value error")
        continue
    except KeyboardInterrupt:
        exit()
    printb(b"%-18.9f %-16s %-6d %-6d %s" % (ts, task, pid, cpu, msg))