Re: [tarantool-patches] Re: [PATCH v2] xrow: print corrupted rows on decoding error.

[Vladimir Davydov <vdavydov.dev@gmail.com>]

On Thu, Apr 04, 2019 at 02:52:25PM +0300, Serge Petrenko wrote:
> 
> Hi!
> 
> > 3 апр. 2019 г., в 12:18, Vladimir Davydov <vdavydov.dev@gmail.com> написал(а):
> > 
> > On Mon, Apr 01, 2019 at 04:09:06PM +0300, Serge Petrenko wrote:
> >> Add row hex printing to log on verbose level. This would be useful
> >> during investigation of errors related to invalid msgpack packet
> >> arrival.
> >> 
> >> Here's some example output:
> >> ```
> >> 2019-04-01 16:04:51.629 [31304] iproto V> Corrupted row is: 3D A5 41 55 99 18 A8 08 C2 40 2B BA 50 12 F6 C6 0B 27 66 1C
> >> 2019-04-01 16:04:51.629 [31304] iproto xrow.c:133 E> ER_INVALID_MSGPACK: Invalid MsgPack - packet header
> >> ```
> >> 
> >> Related to #4040
> >> ---
> >> https://github.com/tarantool/tarantool/tree/sp/xrow-decode-verbose-err
> >> https://github.com/tarantool/tarantool/issues/4040
> >> 
> >> Changes in v2:
> >>  - make xrow_on_decode_err a macro instead of a
> >>    function to preserve line where error occurs.
> >>  - add a test case.
> >>  - always allocate buffer for hex dump with malloc
> >>  - add logging on all errors related to invalid
> >>    msgpack and missing request field.
> >> 
> >> src/box/xrow.c            | 116 ++++++++++++++++++++++++++------------
> >> test/box/net.box.result   |  34 +++++++++++
> >> test/box/net.box.test.lua |  16 ++++++
> >> 3 files changed, 131 insertions(+), 35 deletions(-)
> >> 
> >> diff --git a/src/box/xrow.c b/src/box/xrow.c
> >> index 73d9e739b..fdd15bef3 100644
> >> --- a/src/box/xrow.c
> >> +++ b/src/box/xrow.c
> >> @@ -88,15 +88,49 @@ mp_decode_vclock(const char **data, struct vclock *vclock)
> >> 	return 0;
> >> }
> >> 
> >> +/**
> >> + * Set diagnostics with an error and log the corrupted row
> >> + * which caused the error.
> >> + * Optionally, if log_level is 'verbose' or greater,
> >> + * dump the corrupted row contents in hex to the log.
> >> + *
> >> + * @param what - exception to set.
> >> + * @param desc_str - error description string.
> >> + */
> >> +#define xrow_on_decode_err(_start, _end, _what, _desc_str) do {				\
> >> +	diag_set(ClientError, _what, _desc_str);					\
> >> +											\
> >> +	if (!say_log_level_is_enabled(S_VERBOSE))					\
> >> +		break;									\
> >> +											\
> >> +	size_t _len = 3 * ((const char *)(_end) - (const char *)(_start) + 1);		\
> > 
> > Nit: shouldn't +1 be outside the parentheses?
> 
> Yes, I guess I meant the interval to be inclusive.
> But since it is not, the ‘+1’ should be outside.
> 
> > 
> >> +	char *_buf = (char *)malloc(_len);						\
> > 
> > Nit: we don't usually prefix names with underscores, because this may
> > conflict with libc internal macro definitions.
> 
> Ok. Do you want me to fix it?

Yes, please do and update the branch.