IDS Forum

Re: slow connections

Posted By: Jonathan Smaby
Date: Saturday, 6 December 2008, at 12:02 a.m.

In Response To: Re: slow connections (ILKKA MUSTONEN)

Just my anecdotal analysis: I had a problem once when users called my
office complaining that the database was =B3slow=B2. I could find nothing wron=
g
with my HPUX box, nor with the Informix engine. In fact, the system load
was fairly load, the =B3slowness=B2 turned out to be massive amount of network
traffic at the Core Switch from users with KaZaa, iTunes, and eDonkey file
sharing traffic that was squelching bandwidth on the local network. The
sad thing was, the very same users that complained about slowness were the
same ones using KaZaa, iTunes, and eDonkey.

I=B9m not suggesting that this is causing your specific performance issues,
but it probably wouldn=B9t hurt to query your Network Admin(s) to check for
unusually levels of LAN activity.

**plink-plink** the sound of my 2 cents.

Jonathan Smaby
Pomona College

---
=B3Despite the undeniable facts and indisputable evidence, it=B9s still the
fault of the I.T. staff, we just haven=B9t yet figured out how.=B2

From: ILKKA MUSTONEN <i.will.sue.you@gmail.com>
Reply-To: <ids@iiug.org>
Date: Thu, 4 Dec 2008 12:56:31 -0500 (EST)
To: <ids@iiug.org>
Subject: Re: slow connections [14218]

> My idea :=20
>=20
> - OS level such as kernel parameter, error log from system
> , i/o busy=20
> - Network level such as network card errors , network log
>=20
> For IDS :=20
> - Check point duration and check point interval (system will be blocked
while doing checkpoint)
> - try to change=20
>=20
> NETTYPE soctcp,4,100,NET
> to=20
>=20
> NETTYPE soctcp,1,400,NET (or 2,200) because you have only 3VPs , too much
poll thread will affect VPs load
> - Why you use "AFF_NPROCS 0" , try "AFF_NPROCS 3" and ensure that AFF_SPR=
OC
is the correct no.=20
>=20
> Jakkrit A.=20

On OS level, which particular kernel parameter, there's quite a few of them=
?

There is nothing in the system errlog.

Disk I/O (Ultra SCSI 320) seems fine according to various tools AND other
programs/applications on the server run without any hiccups. There are
three informix instances on this server, only this one is having OCCASIONAL
congestion. When the slowness is occurring, even locally accessing the
instance with dbaccess is poor, meanwhile you can get instantaneous connect
to the other two instances on the server.

Can't find anything wrong with the network either. Here's some stats:
-------------------------------------------------------------
ETHERNET STATISTICS (ent0) :
Device Type: 2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902)
Elapsed Time: 14 days 22 hours 41 minutes 1 seconds

Transmit Statistics: Receive Statistics:
-------------------- -------------------
Packets: 199837212 Packets: 247648973
Bytes: 178970782328 Bytes: 60691832796
Interrupts: 0 Interrupts: 240159233
Transmit Errors: 0 Receive Errors: 0
Packets Dropped: 0 Packets Dropped: 0

Bad Packets: 0=20
Max Packets on S/W Transmit Queue: 51
S/W Transmit Queue Overflow: 0
Current S/W+H/W Transmit Queue Length: 1

Elapsed Time: 14 days 22 hours 41 minutes 0 seconds
Broadcast Packets: 25403 Broadcast Packets: 3102430
Multicast Packets: 0 Multicast Packets: 27979
No Carrier Sense: 0 CRC Errors: 0
DMA Underrun: 0 DMA Overrun: 0
Lost CTS Errors: 0 Alignment Errors: 0
Max Collision Errors: 0 No Resource Errors: 0
Late Collision Errors: 0 Receive Collision Errors: 0
Deferred: 0 Packet Too Short Errors: 0
SQE Test: 0 Packet Too Long Errors: 0
Timeout Errors: 0 Packets Discarded by Adapter: 0
Single Collision Count: 0 Receiver Start Count: 0
Multiple Collision Count: 0
Current HW Transmit Queue Length: 1

General Statistics:
-------------------
No mbuf Errors: 0=20
Adapter Reset Count: 0
Adapter Data Rate: 2000
Driver Flags: Up Broadcast Running

Simplex 64BitSupport ChecksumOffload

PrivateSegment LargeSend DataRateSet

2-Port 10/100/1000 Base-TX PCI-X Adapter (14108902) Specific Statistics:
------------------------------------------------------------------------
Link Status : Up=20
Media Speed Selected: Auto negotiation
Media Speed Running: 1000 Mbps Full Duplex
PCI Mode: PCI-X (100-133)
PCI Bus Width: 64-bit
Latency Timer: 144=20
Cache Line Size: 128
Jumbo Frames: Disabled
TCP Segmentation Offload: Enabled
TCP Segmentation Offload Packets Transmitted: 20549136
TCP Segmentation Offload Packet Errors: 0
Transmit and Receive Flow Control Status: Disabled
Transmit and Receive Flow Control Threshold (High): 45056
Transmit and Receive Flow Control Threshold (Low): 24576
Transmit and Receive Storage Allocation (TX/RX): 16/48
-------------------------------------------------------------

For IDS:=20
Checkpoints (every 5 minutes) are generally 0 seconds. Rarely 1 second. So
basically fractions of a second, non-issue.
11:03:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 192 buffers no=
t
flushed.=20
11:08:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 197 buffers no=
t
flushed.=20
11:13:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 197 buffers no=
t
flushed.=20
11:18:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 141 buffers no=
t
flushed.=20
11:23:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 142 buffers no=
t
flushed.=20
11:28:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 175 buffers no=
t
flushed.=20
11:33:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 212 buffers no=
t
flushed.=20
11:38:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 207 buffers no=
t
flushed.=20
11:43:26 Fuzzy Checkpoint Completed: duration was 0 seconds, 184 buffers no=
t
flushed.=20

The NETTYPE parameter used to be NETTYPE soctcp,2,250,NET when this problem
started.=20
Since then it was changed to NETTYPE soctcp,4,100,NET but that did not make
it=20
any better.=20

We haven't configured AFF_NPROCS/AFF_SPROC due to running 3 instances on th=
e
server.=20

Any ideas?=20

--IAM=20

***************************************************************************=
*
***=20
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Messages In This Thread

• slow connections
  ILKKA MUSTONEN -- Monday, 1 December 2008, at 1:57 p.m.
  • Re: slow connections
    jak aka -- Tuesday, 2 December 2008, at 11:35 p.m.
    • Re: slow connections
      ILKKA MUSTONEN -- Thursday, 4 December 2008, at 12:56 p.m.
      • Re: slow connections
        Jonathan Smaby -- Saturday, 6 December 2008, at 12:02 a.m.

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