Hi Prante,
Thanks for your response...
Iam using linux... i already increased wmem to 16MB max but still
seeing low throughput with 64MB netty blob push..
[sara@s0 ~]$ cat /proc/sys/net/core/wmem_default
16777216
[sara@s0 ~]$ cat /proc/sys/net/core/wmem_max
16777216
[sara@s0 ~]$ cat /proc/sys/net/ipv4/tcp_wmem
4096 87380 16777216
Regards,
Saravanan
On Sunday, July 23, 2017 at 6:22:36 PM UTC+5:30, Jörg Prante wrote:
>
> Hi Sara,
>
> are you using Linux ? Did you check socket buffer default write memory
> size?
>
> /proc/sys/net/core/wmem_default
>
> where the default is 256k, and
>
> /proc/sys/net/core/wmem_max
>
> where the default is 1m, so socket options that set a socket write buffer
> size can use values up to 1m.
>
> To change for IPv4, you can modify
>
> /proc/sys/net/ipv4/tcp_wmem
>
> But be careful of huge values like 64m. I do not recommend such extreme
> values. They are not worth the price because each and every socket might be
> able to use such large buffer size for each write operation, which wastes a
> lot of memory, and increases the risk of running out of memory. And,
> because TCP frames can not exceed 64k (and typical MTU for ethernet is 1500
> bytes), there is not much effect. If you care for performance on the Linux
> kernel and network interface level, you would have to use a Linux network
> performance tuning guide like /
> https://access.redhat.com/sites/default/files/attachments/20150325_network_performance_tuning.pdf
>
> Best,
>
> Jörg
>
> On Sunday, July 23, 2017 at 11:22:01 AM UTC+2, Sara wrote:
>>
>>
>> Hi Netty Team,
>>
>> I tried to send one big java object of size 64MB with
>> ctx.writeAndFlush then i see performance drops to 200MB/sec whereas if i
>> send 2MB * 32 times using ctx.writeAndFlush call then iam seeing around
>> 800MB/sec.
>>
>> one thing i noticed during 64MB transfer most of the time EAGAIN
>> happens and EPOLL OUT being added again and again and then write syscall
>> being called. so it may be related to EAGAIN or memory allocation for big
>> object..
>>
>> This i tried with EpollServerSocketChannel class.
>>
>> my requirement here is to send one big java object of size 64MB
>> without performance penalty... can you please suggest how can i split and
>> send the big java object object in to 2MB chunks such that i can avoid the
>> EAGAIN or memory allocation issue.
>>
>> Thanks team for your great work...
>>
>> Regards,
>> Sara
>>
>>
>
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