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From: Flavio Pompermaier <pompermaier@okkam.it>
Date: Thu, 16 Apr 2015 10:21:56 +0200
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 <CAELUF_BKkte4KsCGwqhod+SFviE8cW=NTMyYm_0Ozues8dpJkg@mail.gmail.com>
Subject: Re: Concurrency on fields within operators
To: user <user@flink.apache.org>
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Ok thanks a lot for the confirmation! Thread-safety within operators is
absolutely helpful :)

On Thu, Apr 16, 2015 at 9:20 AM, Robert Metzger <rmetzger@apache.org> wrote:

> Hi Flavio,
>
> tl;dr: they are thread safe.
>
> making a field transient means that it is ignored when serializing the
> class. This is for example useful when you have a non-serializable field in
> your function (you have to initialize it in the open() method then).
> So making it transient or not doesn't change the fields thread safety.
> Flink doesn't call the user defined functions concurrently (=from multiple
> threads), so you don't need to worry about thread safety.
> The only case you need to worry about thread safety in your
> (Rich-)Function is when you're starting threads yourself inside the
> Function.
>
>
> On Thu, Apr 16, 2015 at 9:09 AM, Flavio Pompermaier <pompermaier@okkam.it>
> wrote:
>
>> Hi to all,
>> I have a simple question: are transient fields inside a Rich-Function
>>  (like a RichMapPartition) thread-safe or not?
>>
>> Best,
>> Flavio
>>
>>

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<div dir=3D"ltr">Ok thanks a lot for the confirmation! Thread-safety within=
 operators is absolutely helpful :)<br><div class=3D"gmail_extra"><br><div =
class=3D"gmail_quote">On Thu, Apr 16, 2015 at 9:20 AM, Robert Metzger <span=
 dir=3D"ltr">&lt;<a href=3D"mailto:rmetzger@apache.org" target=3D"_blank">r=
metzger@apache.org</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quot=
e" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">=
<div dir=3D"ltr">Hi Flavio,<div><br></div><div>tl;dr: they are thread safe.=
</div><div><br></div><div>making a field transient means that it is ignored=
 when serializing the class. This is for example useful when you have a non=
-serializable field in your function (you have to initialize it in the open=
() method then).</div><div>So making it transient or not doesn&#39;t change=
 the fields thread safety. Flink doesn&#39;t call the user defined function=
s concurrently (=3Dfrom multiple threads), so you don&#39;t need to worry a=
bout thread safety.</div><div>The only case you need to worry about thread =
safety in your (Rich-)Function is when you&#39;re starting threads yourself=
 inside the Function.</div><div><br></div></div><div><div><div class=3D"gma=
il_extra"><br><div class=3D"gmail_quote">On Thu, Apr 16, 2015 at 9:09 AM, F=
lavio Pompermaier <span dir=3D"ltr">&lt;<a href=3D"mailto:pompermaier@okkam=
.it" target=3D"_blank">pompermaier@okkam.it</a>&gt;</span> wrote:<br><block=
quote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc=
 solid;padding-left:1ex"><div dir=3D"ltr">Hi to all,<div>I have a simple qu=
estion: are transient fields inside a Rich-Function =C2=A0(like a RichMapPa=
rtition) thread-safe or not?<br><div><div><br></div><div>Best,</div><div>Fl=
avio</div><div><div dir=3D"ltr"><p></p><p></p><p></p><p></p></div></div>
</div></div></div>
</blockquote></div></div></div></div></blockquote></div><div><div dir=3D"lt=
r"><br><p></p><p></p><p></p><p></p></div></div>
</div></div>

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