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Re: (ITS#8089) LMDB hangs on mdb_txn_renew0 if MDB_NOSYNC flag is used

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Hello Howard,
Please accept my apologies, the issue was not related to LMDB. There have
been a data race in my code that was only triggered by fast writes.
Sorry for late answer, - your e-mail landed into the spam-folder, and I
just found it.

With best regards,
Pavel.

2015-04-16 8:04 GMT+06:00 Howard Chu <hyc@symas.com>:

> pk@dbic.pro wrote:
>
>> Full_Name: Pavel Kraynyukhov
>> Version: only LMDB from git and lmdb-0.9.14
>> OS: Gentoo Linux
>> URL: ftp://ftp.openldap.org/incoming/
>> Submission from: (NULL) (37.99.47.171)
>>
>>
>> Hello there, I have ran into an issue with LMDB, which I can reproduce at
>> will,
>> but it seems a specific one. The git commit is
>> 3368d1f5e243225cba4d730fba19ff600798ebe3
>> And this commit and my issue seems to be related.
>>
>> 1. I use MDB_NOTLS flag on environment open.
>> 2. if  I use MDB_NOSYNC flag for LMDB environment, the writer thread is
>> stuck
>> after several transactions (writer thread backtrace):
>>
>
>  P.S. tested against system provided lmdb version 0.9.14 and result is the
>> same.
>> So this maybe not related to latest commit in git.
>>
>
> If you're having this problem in 0.9.14 then it is certainly not related
> to 3368d1f5e243225cba4d730fba19ff600798ebe3.
>
> You confirm that the issue does not occur in 0.9.13? Can you upload a test
> case demonstrating the problem?
>
> --
>   -- Howard Chu
>   CTO, Symas Corp.           http://www.symas.com
>   Director, Highland Sun     http://highlandsun.com/hyc/
>   Chief Architect, OpenLDAP  http://www.openldap.org/project/
>

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<div dir=3D"ltr"><div><div><div><div>Hello Howard,<br></div>Please accept m=
y apologies, the issue was not related to LMDB. There have been a data race=
 in my code that was only triggered by fast writes.<br></div>Sorry for late=
 answer, - your e-mail landed into the spam-folder, and I just found it.<br=
><br></div>With best regards,<br></div>Pavel.<br><div><div><div><div><div c=
lass=3D"gmail_extra"><br><div class=3D"gmail_quote">2015-04-16 8:04 GMT+06:=
00 Howard Chu <span dir=3D"ltr">&lt;<a href=3D"mailto:hyc@symas.com"; target=
=3D"_blank">hyc@symas.com</a>&gt;</span>:<br><blockquote class=3D"gmail_quo=
te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"=
><a href=3D"mailto:pk@dbic.pro"; target=3D"_blank">pk@dbic.pro</a> wrote:<br=
>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
Full_Name: Pavel Kraynyukhov<br>
Version: only LMDB from git and lmdb-0.9.14<br>
OS: Gentoo Linux<br>
URL: <a href=3D"ftp://ftp.openldap.org/incoming/"; target=3D"_blank">ftp://f=
tp.openldap.org/incoming/</a><br>
Submission from: (NULL) (37.99.47.171)<br>
<br>
<br>
Hello there, I have ran into an issue with LMDB, which I can reproduce at w=
ill,<br>
but it seems a specific one. The git commit is<br>
3368d1f5e243225cba4d730fba19ff600798ebe3<br>
And this commit and my issue seems to be related.<br>
<br>
1. I use MDB_NOTLS flag on environment open.<br>
2. if=C2=A0 I use MDB_NOSYNC flag for LMDB environment, the writer thread i=
s stuck<br>
after several transactions (writer thread backtrace):<br>
</blockquote>
<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
P.S. tested against system provided lmdb version 0.9.14 and result is the s=
ame.<br>
So this maybe not related to latest commit in git.<br>
</blockquote>
<br>
If you&#39;re having this problem in 0.9.14 then it is certainly not relate=
d to 3368d1f5e243225cba4d730fba19ff600798ebe3.<br>
<br>
You confirm that the issue does not occur in 0.9.13? Can you upload a test =
case demonstrating the problem?<span class=3D"HOEnZb"><font color=3D"#88888=
8"><br>
<br>
-- <br>
=C2=A0 -- Howard Chu<br>
=C2=A0 CTO, Symas Corp.=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0<a href=3D"=
http://www.symas.com"; target=3D"_blank">http://www.symas.com</a><br>
=C2=A0 Director, Highland Sun=C2=A0 =C2=A0 =C2=A0<a href=3D"http://highland=
sun.com/hyc/" target=3D"_blank">http://highlandsun.com/hyc/</a><br>
=C2=A0 Chief Architect, OpenLDAP=C2=A0 <a href=3D"http://www.openldap.org/p=
roject/" target=3D"_blank">http://www.openldap.org/project/</a><br>
</font></span></blockquote></div><br><br></div></div></div></div></div></di=
v>

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