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

[Serge Petrenko]

Hi!

> 3 апр. 2019 г., в 12:18, Vladimir Davydov <vdavydov.dev at 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?

> 
> Other than that this patch looks good to me. Do we need it in 1.10?

Yes, we need it in 1.10.