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<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Hi,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Basically, we are using
Amazon's EC2 servers as memcached servers. <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>So as and when we see
an increase in traffic/load, we expect to add more EC2 servers to the memcached
cloud. And when the traffic/load subsides (lets say after a week or so), we might
remove a few servers from the cloud. <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>In such a scenario, if
using normal hashing, I believe we would have to flush everything when
adding/removing memcached servers. <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Do you think doing this
might cause the system to go in a spin and might be a risky proposition, and so
we should rather consider using consistent hashing?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Or do you think this is
not a big deal and we should rather use the regular hashing (which is more
stable)?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Please let me know your
comments on this.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Regards,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 color=navy face=Verdana><span
style='font-size:10.0pt;font-family:Verdana;color:navy'>Ajinkya</span></font> <o:p></o:p></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>-----Original Message-----<br>
From: Mikael Johansson [mailto:mikael@synd.info] <br>
Sent: Thursday, August 30, 2007 11:03 AM<br>
To: Ajinkya Nahar<br>
Cc: memcached@lists.danga.com; sunil@truesparrow.com; 'Nishith Shah'<br>
Subject: Re: Regarding Consistent Hashing....</span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Hi,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>I believe there's already people using consistent hashing on large<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>installs out there. As to the pecl/memcache client the code is not<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>released and still in CVS, but it is stable (and certainly ready to be<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>evaluated/tested), also a release is coming up so you can either wait<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>for that or build from source like<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> cvs -d :pserver:cvsread@cvs.php.net:/repository checkout
pecl/memcache<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> cd pecl/memcache<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> phpize<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> ./configure<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> make && make install<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Enable it by setting an php.ini entry like<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'> memcache.hash_strategy = consistent<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Please note that the consistent hashing implementation might still<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>change in the future when a standard is reached on the subject.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>//Mikael<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>Ajinkya Nahar wrote:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Hi all,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> I want to know whether consistent hashing technique can be used in<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> production environment.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Is it still too young or is it of production quality?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Also, what configuration needs to be done in the PHP client when
using<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> consistent hashing?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Please let me know.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Thanks in advance.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Regards,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> Ajinkya<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'>> <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=2 face="Courier New"><span style='font-size:
10.0pt'><o:p> </o:p></span></font></p>
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