Sorry for asking this topic, but after reading the tool's documentation and the similar ticket to my question (https://github.com/esnet/iperf/issues/343), I still don't really understand/know the meaning of the Retr column in a TCP measurement, and I do not get how to "use" it :-(
Let's say there is a result, like below, where are 5 retries. I got, these are the number of TCP segments retransmitted, but
were these retransmitted successfully, or they were just retried to send and not know about the result of that?
If I would like to see some kind of summa at the end in percentage (%), can the tool print it, similar to the UDP measurement? If not, how can I get the summa sent/received segments for compute the failure ratio?
Version of the tool:
>batman#bat-image:~$ iperf3 -v
iperf 3.8.1 (cJSON 1.7.13)
Linux bat-image 4.15.0-106-generic #107-Ubuntu SMP Thu Jun 4 11:27:52 UTC 2020 x86_64
Optional features available: CPU affinity setting, IPv6 flow label, TCP congestion algorithm setting, sendfile / zerocopy, socket pacing
batman#bat-image:~$
OS:
Ubuntu-18.04
batman#bat-image:~$ uname -aLinux bat-image 4.15.0-106-generic #107-Ubuntu SMP Thu Jun 4 11:27:52 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
batman#bat-image:~$
The log:
batman#bat-image:~$iperf3 -c 192.168.122.1 -f K -B 192.168.122.141 -b 10m -t 10
Connecting to host 192.168.122.1, port 5201
[ 5] local 192.168.122.141 port 34665 connected to 192.168.122.1 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 1.25 MBytes 10.5 Mbits/sec 0 297 KBytes
[ 5] 1.00-2.00 sec 1.25 MBytes 10.5 Mbits/sec 0 297 KBytes
[ 5] 2.00-3.00 sec 1.12 MBytes 9.43 Mbits/sec 0 297 KBytes
[ 5] 3.00-4.00 sec 1.25 MBytes 10.5 Mbits/sec 0 297 KBytes
[ 5] 4.00-5.00 sec 1.12 MBytes 9.43 Mbits/sec 0 297 KBytes
[ 5] 5.00-6.00 sec 1.25 MBytes 10.5 Mbits/sec 0 297 KBytes
[ 5] 6.00-7.00 sec 1.12 MBytes 9.44 Mbits/sec 2 1.41 KBytes
[ 5] 7.00-8.00 sec 512 KBytes 4.19 Mbits/sec 1 1.41 KBytes
[ 5] 8.00-9.00 sec 0.00 Bytes 0.00 Mbits/sec 1 1.41 KBytes
[ 5] 9.00-10.00 sec 0.00 Bytes 0.00 Mbits/sec 1 1.41 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 8.87 MBytes 7.44 Mbits/sec 5 sender
[ 5] 0.00-16.91 sec 7.62 MBytes 3.78 Mbits/sec receiver
iperf Done.
thanks for your help,
/Robi
In iperf3 the column Retr stands for Retransmitted TCP packets and indicates the number of TCP packets that had to be sent again (=retransmitted).
The lower the value in Retr the better. An optimal value would be 0, meaning that no matter how many TCP packets have been sent, not a single one had to be resent. A value greater than zero indicates packet losses which might arise from network congestion (too much traffic) or corruption due to faulty hardware.
Your original issue on Github has also been answered (source): https://github.com/esnet/iperf/issues/343
You are asking about the different outputs of iperf3 based on whether you test UDP or TCP.
When using UDP it's acceptable for packets to not arrive at the destination. To indicate the quality of the connection/ data transfer you get a percentage of how many packets did not arrive at the destination.
When using TCP all packets are supposed to reach the destination and are checked for missing or corrupted ones (hence Transmission Control Protocol). If a packet is missing it get's retransmitted. To indicate the quality of the connection you get a number of how many packets had to be retransmitted.
So both the percentage with UDP and the Retr count with TCP are quality indicators that are adjusted to the specifics of each protocol.
If you are wondering what the Cwnd column means, it stands for Congestion Window. The Congestion Window is a TCP state variable that limits the amount of data the TCP can send into the network before receiving an ACK.
Source: https://blog.stackpath.com/glossary-cwnd-and-rwnd/
Related
I use tcpdump to catch some tcp packets, when analyzing them according to ip/tcp packet schema, the packet seems to be broken. Here is a sample packet I got from tcpdump output. Is any one familiar with them?
Should not the first 4 bit of ip packet always be 0100 in under ipv4?
ip packet: https://en.wikipedia.org/wiki/IPv4
some examples: http://mike.passwall.com/networking/samplepacket.html
13:11:43.330397 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 60)
172.16.0.14.16668 > 36.24.146.114.64853: Flags [S.], cksum 0xdc0f (correct), seq 3029391223, ack 129060479, win 14480, options [mss 1460,sackOK,TS val 1254469916 ecr 1492278057,nop,wscale 6], length 0
0x0000: feee 809f 3247 5254 0054 aa9f 0800 4500 ....2GRT.T....E.
0x0010: 003c 0000 4000 4006 d813 ac10 000e 2418 .<..#.#.......$.
0x0020: 9272 411c fd55 b490 d777 07b1 4e7f a012 .rA..U...w..N...
0x0030: 3890 dc0f 0000 0204 05b4 0402 080a 4ac5 8.............J.
uname -a
# Linux VM_0_14_centos 2.6.32-754.2.1.el6.x86_64 #1 SMP Fri Jul 13 12:50:12 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
# tcpdump
tcpdump tcp -vv -XX -n -i eth0 port 16668
0x0000: feee 809f 3247 5254 0054 aa9f 0800 4500 ....2GRT.T....E.
The first 14 bytes are from the link layer (EN10MB). The IP layer only starts with 4500, where the 4 (binary 0100) are the first 4 bits which describe the version number, i.e. IP version 4.
These link layer data are explicitly requested by the -XX option which is used by the OP as pointed out in a comment by David Hoelzer. To cite from the documentation of tcpdump:
-XX When parsing and printing, in addition to printing the headers of each packet, print the data of each packet, including its link level header, in hex and ASCII.
OFFICIAL EDIT:
I thank you so much for your help but I am still encountering problems.
My ffserver.conf file is like this:
# Port on which the server is listening. You must select a different
# port from your standard HTTP web server if it is running on the same
# computer.
HTTPPort 8090
# Address on which the server is bound. Only useful if you have
# several network interfaces.
HTTPBindAddress 0.0.0.0
# Number of simultaneous HTTP connections that can be handled. It has
# to be defined *before* the MaxClients parameter, since it defines the
# MaxClients maximum limit.
MaxHTTPConnections 2000
# Number of simultaneous requests that can be handled. Since FFServer
# is very fast, it is more likely that you will want to leave this high
# and use MaxBandwidth, below.
MaxClients 1000
# This the maximum amount of kbit/sec that you are prepared to
# consume when streaming to clients.
MaxBandwidth 1000
# Access log file (uses standard Apache log file format)
# '-' is the standard output.
CustomLog -
##################################################################
# Definition of the live feeds. Each live feed contains one video
# and/or audio sequence coming from an ffmpeg encoder or another
# ffserver. This sequence may be encoded simultaneously with several
# codecs at several resolutions.
<Feed feed1.ffm>
# You must use 'ffmpeg' to send a live feed to ffserver. In this
# example, you can type:
#
# ffmpeg http://localhost:8090/feed1.ffm
# ffserver can also do time shifting. It means that it can stream any
# previously recorded live stream. The request should contain:
# "http://xxxx?date=[YYYY-MM-DDT][[HH:]MM:]SS[.m...]".You must specify
# a path where the feed is stored on disk. You also specify the
# maximum size of the feed, where zero means unlimited. Default:
# File=/tmp/feed_name.ffm FileMaxSize=5M
File /tmp/feed1.ffm
FileMaxSize 200K
# You could specify
# ReadOnlyFile /saved/specialvideo.ffm
# This marks the file as readonly and it will not be deleted or updated.
# Specify launch in order to start ffmpeg automatically.
# First ffmpeg must be defined with an appropriate path if needed,
# after that options can follow, but avoid adding the http:// field
#Launch ffmpeg
# Only allow connections from localhost to the feed.
#ACL allow 127.0.0.1
#ACL allow 189.34.0.158
</Feed>
##################################################################
# Now you can define each stream which will be generated from the
# original audio and video stream. Each format has a filename (here
# 'test1.mpg'). FFServer will send this stream when answering a
# request containing this filename.
<Stream test1.mpg>
# coming from live feed 'feed1'
Feed feed1.ffm
# Format of the stream : you can choose among:
# mpeg : MPEG-1 multiplexed video and audio
# mpegvideo : only MPEG-1 video
# mp2 : MPEG-2 audio (use AudioCodec to select layer 2 and 3 codec)
# ogg : Ogg format (Vorbis audio codec)
# rm : RealNetworks-compatible stream. Multiplexed audio and video.
# ra : RealNetworks-compatible stream. Audio only.
# mpjpeg : Multipart JPEG (works with Netscape without any plugin)
# jpeg : Generate a single JPEG image.
# asf : ASF compatible streaming (Windows Media Player format).
# swf : Macromedia Flash compatible stream
# avi : AVI format (MPEG-4 video, MPEG audio sound)
Format mpeg
# Bitrate for the audio stream. Codecs usually support only a few
# different bitrates.
AudioBitRate 32
# Number of audio channels: 1 = mono, 2 = stereo
AudioChannels 1
# Sampling frequency for audio. When using low bitrates, you should
# lower this frequency to 22050 or 11025. The supported frequencies
# depend on the selected audio codec.
AudioSampleRate 44100
# Bitrate for the video stream
VideoBitRate 64
# Ratecontrol buffer size
VideoBufferSize 40
# Number of frames per second
VideoFrameRate 3
# Size of the video frame: WxH (default: 160x128)
# The following abbreviations are defined: sqcif, qcif, cif, 4cif, qqvga,
# qvga, vga, svga, xga, uxga, qxga, sxga, qsxga, hsxga, wvga, wxga, wsxga,
# wuxga, woxga, wqsxga, wquxga, whsxga, whuxga, cga, ega, hd480, hd720,
# hd1080
VideoSize 160x128
# Transmit only intra frames (useful for low bitrates, but kills frame rate).
#VideoIntraOnly
# If non-intra only, an intra frame is transmitted every VideoGopSize
# frames. Video synchronization can only begin at an intra frame.
VideoGopSize 12
# More MPEG-4 parameters
# VideoHighQuality
# Video4MotionVector
# Choose your codecs:
#AudioCodec mp2
#VideoCodec mpeg1video
# Suppress audio
#NoAudio
# Suppress video
#NoVideo
#VideoQMin 3
#VideoQMax 31
# Set this to the number of seconds backwards in time to start. Note that
# most players will buffer 5-10 seconds of video, and also you need to allow
# for a keyframe to appear in the data stream.
#Preroll 15
# ACL:
# You can allow ranges of addresses (or single addresses)
#ACL ALLOW <first address> <last address>
# You can deny ranges of addresses (or single addresses)
#ACL DENY <first address> <last address>
# You can repeat the ACL allow/deny as often as you like. It is on a per
# stream basis. The first match defines the action. If there are no matches,
# then the default is the inverse of the last ACL statement.
#
# Thus 'ACL allow localhost' only allows access from localhost.
# 'ACL deny 1.0.0.0 1.255.255.255' would deny the whole of network 1 and
# allow everybody else.
</Stream>
##################################################################
# Example streams
# Multipart JPEG
#<Stream test.mjpg>
#Feed feed1.ffm
#Format mpjpeg
#VideoFrameRate 2
#VideoIntraOnly
#NoAudio
#Strict -1
#</Stream>
# Single JPEG
#<Stream test.jpg>
#Feed feed1.ffm
#Format jpeg
#VideoFrameRate 2
#VideoIntraOnly
##VideoSize 352x240
#NoAudio
#Strict -1
#</Stream>
# Flash
#<Stream test.swf>
#Feed feed1.ffm
#Format swf
#VideoFrameRate 2
#VideoIntraOnly
#NoAudio
#</Stream>
# ASF compatible
<Stream test.asf>
Feed feed1.ffm
Format asf
VideoFrameRate 15
VideoSize 352x240
VideoBitRate 256
VideoBufferSize 40
VideoGopSize 30
AudioBitRate 64
StartSendOnKey
</Stream>
# MP3 audio
#<Stream test.mp3>
#Feed feed1.ffm
#Format mp2
#AudioCodec mp3
#AudioBitRate 64
#AudioChannels 1
#AudioSampleRate 44100
#NoVideo
#</Stream>
# Ogg Vorbis audio
#<Stream test.ogg>
#Feed feed1.ffm
#Metadata title "Stream title"
#AudioBitRate 64
#AudioChannels 2
#AudioSampleRate 44100
#NoVideo
#</Stream>
# Real with audio only at 32 kbits
#<Stream test.ra>
#Feed feed1.ffm
#Format rm
#AudioBitRate 32
#NoVideo
#NoAudio
#</Stream>
# Real with audio and video at 64 kbits
#<Stream test.rm>
#Feed feed1.ffm
#Format rm
#AudioBitRate 32
#VideoBitRate 128
#VideoFrameRate 25
#VideoGopSize 25
#NoAudio
#</Stream>
##################################################################
# A stream coming from a file: you only need to set the input
# filename and optionally a new format. Supported conversions:
# AVI -> ASF
#<Stream file.rm>
#File "/usr/local/httpd/htdocs/tlive.rm"
#NoAudio
#</Stream>
#<Stream file.asf>
#File "/usr/local/httpd/htdocs/test.asf"
#NoAudio
#Metadata author "Me"
#Metadata copyright "Super MegaCorp"
#Metadata title "Test stream from disk"
#Metadata comment "Test comment"
#</Stream>
##################################################################
# RTSP examples
#
# You can access this stream with the RTSP URL:
# rtsp://localhost:5454/test1-rtsp.mpg
#
# A non-standard RTSP redirector is also created. Its URL is:
# http://localhost:8090/test1-rtsp.rtsp
#<Stream test1-rtsp.mpg>
#Format rtp
#File "/usr/local/httpd/htdocs/test1.mpg"
#</Stream>
# Transcode an incoming live feed to another live feed,
# using libx264 and video presets
#<Stream live.h264>
#Format rtp
#Feed feed1.ffm
#VideoCodec libx264
#VideoFrameRate 24
#VideoBitRate 100
#VideoSize 480x272
#AVPresetVideo default
#AVPresetVideo baseline
#AVOptionVideo flags +global_header
#
#AudioCodec libfaac
#AudioBitRate 32
#AudioChannels 2
#AudioSampleRate 22050
#AVOptionAudio flags +global_header
#</Stream>
##################################################################
# SDP/multicast examples
#
# If you want to send your stream in multicast, you must set the
# multicast address with MulticastAddress. The port and the TTL can
# also be set.
#
# An SDP file is automatically generated by ffserver by adding the
# 'sdp' extension to the stream name (here
# http://localhost:8090/test1-sdp.sdp). You should usually give this
# file to your player to play the stream.
#
# The 'NoLoop' option can be used to avoid looping when the stream is
# terminated.
#<Stream test1-sdp.mpg>
#Format rtp
#File "/usr/local/httpd/htdocs/test1.mpg"
#MulticastAddress 224.124.0.1
#MulticastPort 5000
#MulticastTTL 16
#NoLoop
#</Stream>
##################################################################
# Special streams
# Server status
<Stream stat.html>
Format status
# Only allow local people to get the status
ACL allow localhost
ACL allow 192.168.0.0 192.168.255.255
#FaviconURL http://pond1.gladstonefamily.net:8080/favicon.ico
</Stream>
# Redirect index.html to the appropriate site
<Redirect index.html>
URL http://www.ffmpeg.org/
</Redirect>
I started my server and executed:
ffserver -d -f /usr/share/doc/ffmpeg-2.6.8/ffserver.conf
No error message and everything looks fine.
After that I execute this (in your answer, I think you forgot the port number):
ffmpeg -i "rtsp://200.180.90.95:554/onvif1" -r 25 -s 640x480 -c:v libx264 -flags +global_header -f flv "http://45.79.207.38:8090/feed1.ffm"
Then I get this log:
libavutil 54. 20.100 / 54. 20.100
libavcodec 56. 26.100 / 56. 26.100
libavformat 56. 25.101 / 56. 25.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 11.102 / 5. 11.102
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
[h264 # 0x1a23580] RTP: missed 1 packets
[pcm_alaw # 0x1a24360] RTP: missed 2 packets
[h264 # 0x1a23580] RTP: missed 1 packets
Invalid UE golomb code
[h264 # 0x1a23580] cbp too large (3199971767) at 76 33
[h264 # 0x1a23580] error while decoding MB 76 33
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 933 DC, 933 AC, 933 MV errors in P frame
[h264 # 0x1a23580] RTP: missed 1 packets
[h264 # 0x1a23580] cbp too large (62) at 50 24
[h264 # 0x1a23580] error while decoding MB 50 24
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 1679 DC, 1679 AC, 1679 MV errors in P frame
[h264 # 0x1a23580] RTP: missed 2 packets
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 1965 DC, 1965 AC, 1965 MV errors in P frame
[pcm_alaw # 0x1a24360] RTP: missed 1 packets
Last message repeated 1 times
[h264 # 0x1a23580] RTP: missed 3 packets
[h264 # 0x1a23580] mb_type 49 in P slice too large at 74 25
[h264 # 0x1a23580] error while decoding MB 74 25
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 1575 DC, 1575 AC, 1575 MV errors in P frame
[h264 # 0x1a23580] RTP: missed 2 packets
[h264 # 0x1a23580] P sub_mb_type 29 out of range at 30 26
[h264 # 0x1a23580] error while decoding MB 30 26
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 1539 DC, 1539 AC, 1539 MV errors in P frame
[h264 # 0x1a23580] RTP: missed 1 packets
[h264 # 0x1a23580] out of range intra chroma pred mode at 72 29
[h264 # 0x1a23580] error while decoding MB 72 29
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 1257 DC, 1257 AC, 1257 MV errors in P frame
[h264 # 0x1a23580] RTP: missed 3 packets
[h264 # 0x1a23580] negative number of zero coeffs at 48 5
[h264 # 0x1a23580] error while decoding MB 48 5
[h264 # 0x1a23580] Cannot use next picture in error concealment
[h264 # 0x1a23580] concealing 3201 DC, 3201 AC, 3201 MV errors in P frame
[pcm_alaw # 0x1a24360] RTP: missed 1 packets
[rtsp # 0x1a20ee0] decoding for stream 0 failed
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, rtsp, from 'rtsp://200.180.90.95:554/onvif1':
Metadata:
title : H.264 Video, RtspServer_0.0.0.2
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0: Video: h264 (Baseline), yuv420p, 1280x720, 90k tbr, 90k tbn, 180k tbc
Stream #0:1: Audio: pcm_alaw, 8000 Hz, 1 channels, s16, 64 kb/s
[libx264 # 0x1b728a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI2
[libx264 # 0x1b728a0] profile High, level 3.0
[libx264 # 0x1b728a0] 264 - core 142 r2495 6a301b6 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=1 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[flv # 0x1a66300] FLV does not support sample rate 8000, choose from (44100, 22050, 11025)
[flv # 0x1a66300] Audio codec mp3 not compatible with flv
Output #0, flv, to 'http://45.79.207.38:8090/feed1.ffm':
Metadata:
title : H.264 Video, RtspServer_0.0.0.2
encoder : Lavf56.25.101
Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv420p, 640x480, q=-1--1, 25 fps, 1k tbn, 25 tbc
Metadata:
encoder : Lavc56.26.100 libx264
Stream #0:1: Audio: mp3 (libmp3lame) ([2][0][0][0] / 0x0002), 8000 Hz, mono, s16p
Metadata:
encoder : Lavc56.26.100 libmp3lame
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (pcm_alaw (native) -> mp3 (libmp3lame))
Could not write header for output file #0 (incorrect codec parameters ?): Function not implemented
I am doing this in a clean install of CENTOS, no customization. Could you please helpe me?
When you installed ffmpeg (yum install ffmpeg), along with ffmpeg,ffserver is also installed.
Step 1: Configure ffserver (config file located in /etc/ffserver.conf), configure HTTPPort to any available port. <Feed feed1.ffm> .... </Feed> this block describes the input point for server feed. and <Stream test1.mpg> .. </Stream> block in output. Final output stream is decided by this block.
Step 2: Start ffserver by typing ffserver in command line (if you want to run it in background then 'nohup ffserver &')
Step 3: ffmpeg -i "rtsp://200.180.90.95:554/onvif1" -r 25 -s 640x480 -c:v libx264 -flags +global_header -f flv "http://45.79.207.38:/feed1.ffm"
NOTE: Streaming video requires higher internet bandwidth.
I am using iperf to test the connection between two machines (WiFi+AP), one runs Ubuntu14, and the other is Win7. Both are on the same subnet.
The problem is that the results varies very much over time, and varies from run to run! and I couldn't figure out the exact reasons?
results snip:
[ 4] local 192.168.0.135 port 5001 connected with 192.168.0.147 port 42003
[ ID] Interval Transfer Bandwidth
[ 4] 0.0- 5.0 sec 2.77 MBytes 4.64 Mbits/sec
[ 4] 5.0-10.0 sec 3.68 MBytes 6.17 Mbits/sec
[ 4] 10.0-15.0 sec 3.42 MBytes 5.74 Mbits/sec
[ 4] 15.0-20.0 sec 1.23 MBytes 2.07 Mbits/sec
[ 4] 20.0-25.0 sec 1.10 MBytes 1.85 Mbits/sec
[ 4] 25.0-30.0 sec 1.04 MBytes 1.74 Mbits/sec
[ 4] 30.0-35.0 sec 1.51 MBytes 2.54 Mbits/sec
command # Win Server
iperf -c IP -i 5 -t 60
Command # Ub Client
iperf -s -i 5
Could anyone help me explaining why it varies that much? and how to correctly probe the connection between the two machines for later comparisons?
Your results draw expected variation.
Anyway, this fluctuation would be due to different factors:
Network traffic. Are those nodes alone on the switch/router/network or they are influenced by other nodes?
Processors traffic. Are you running processes/services/daemons that may slow down your processors so that your processor may lag your transmission?
Indeed, several factors would be behind.
i'm trying to subset a large dataframe by date field ad facing strange behaviour:
1) find interesting time interval:
> ld[ld$bps>30000000,]
Date.first.seen Duration Proto Src.IP.Addr Src.Pt Dst.IP.Addr Dst.Pt Tos Packets Bytes bps
1400199 2015-03-31 13:52:24 0.008 TCP 3.3.3.3 3128 4.4.4.4 65115 0 39 32507 32500000
1711899 2015-03-31 14:58:10 0.004 TCP 3.3.3.3 3128 4.4.4.7 49357 0 29 23830 47700000
2) and try to look whats happening on that second:
> ld[ld$Date.first.seen=="2015-03-31 13:52:24",]
Date.first.seen Duration Proto Src.IP.Addr Src.Pt Dst.IP.Addr Dst.Pt Tos Packets Bytes bps
1401732 2015-03-31 13:52:24 17.436 TCP 3.3.3.3 3128 6.6.6.6 51527 0 3 1608 737
don't really understand the behavior - i should get way more results.
for example
> ld[1399074,]
Date.first.seen Duration Proto Src.IP.Addr Src.Pt Dst.IP.Addr Dst.Pt Tos Packets Bytes bps
1399074 2015-03-31 13:52:24 0.152 TCP 10.10.10.10 3128 11.11.11.11 62375 0 8 3910 205789
for date i use POSIXlt
> str(ld)
'data.frame': 2657583 obs. of 11 variables:
$ Date.first.seen: POSIXlt, format: "2015-03-31 06:00:00" "2015-03-31 06:00:00" "2015-03-31 06:00:00" "2015-03-31 06:00:01" ...
...
would appreciate any assistance. thanks!
POSIXlt may carry additional info which is supressed when printing the entire data.frame, timezone, daylight savings etc. Have a look at https://stat.ethz.ch/R-manual/R-devel/library/base/html/DateTimeClasses.html.
Printing only the POSIXlt variable (ld$Date.first.seen) does generally supply at least some of this additional information.
If you're not for some particular reason required to keep your variable in the POSIXlt and if you don't need the extra functionality the format enables, a simple:
ld$Date.first.seen = as.character(ld$Date.first.seen)
Added before your subset statement will probably solve your problem.
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I am having a weird TCP issue that makes no sense at all. I am tearing my hair out.
When downloading a file from Amazon S3 (and only Amazon S3- every other site works fine) some percentage of the time the connections dies. This only happens from our servers in Seattle with a web server behind a NAT router. Connecting directly from the router works fine. From our servers here in Victoria everything works fine, and we can't replicate this at all.
Web server in Seattle (tried 10 different servers) -> SNAT router (2 different routers; old kernels and new kernels) -> Amazon S3 = doesn't work ~10% of the time
Web server in Seattle -> SNAT router -> any other website = works
Router box -> Amazon S3 = works
Web server in Victoria -> SNAT router in Victoria -> Amazon S3 = works
Things I've tried:
Disabling window scaling
Lowering the window size
upgrading the router to the newest kernel
Disabling the firewall entirely
In the failure case Amazon (or something along the way) sends us a 868 length packet instead of the expected 1500 byte packet. The server upon seeing the packets replies with a RST packet (error has occurred) and the connection is torn down.
Any help would be greatly appreciated!
Below are two TCP dumps-
------------ Begin Error Case TCP Dump -------------
tcpdump -r /tmp/s3doesntwork-died
reading from file /tmp/s3doesntwork-died, link-type EN10MB (Ethernet)
19:58:42.542189 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: S 193799772:193799772(0) win 5840 <mss 1460,sackOK,timestamp 760821159 0,nop,wscale 5>
19:58:42.544115 IP 189-81.amazon.com.www > locum.sparklit.com.39491: S 3148664267:3148664267(0) ack 193799773 win 8190 <mss 1460,nop,wscale 6,nop,nop,sackOK>
19:58:42.545176 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 1 win 183
19:58:42.545184 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: P 1:212(211) ack 1 win 183
19:58:42.548113 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . ack 212 win 916
19:58:42.558108 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 1:1461(1460) ack 212 win 916
19:58:42.558117 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 1461:2921(1460) ack 212 win 916
19:58:42.558123 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 2921:4381(1460) ack 212 win 916
19:58:42.558128 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 4381:5841(1460) ack 212 win 916
19:58:42.559108 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 5841:7301(1460) ack 212 win 916
19:58:42.559118 IP 189-81.amazon.com.www > locum.sparklit.com.39491: . 7301:8129(828) ack 212 win 916
19:58:42.559138 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: R 193799984:193799984(0) win 0
19:58:42.559169 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 1461 win 274
19:58:42.559176 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 2921 win 365
19:58:42.559180 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 4381 win 457
19:58:42.559188 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 5841 win 548
19:58:42.560167 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: . ack 7301 win 639
19:58:45.308618 IP locum.sparklit.com.39491 > 189-81.amazon.com.www: F 212:212(0) ack 7301 win 639
19:58:45.310512 IP 189-81.amazon.com.www > locum.sparklit.com.39491: R 3148671568:3148671568(0) win 8201
Update: Traceroute to Amazon
1 64.34.33.195 (64.34.33.195) 0.795 ms 0.775 ms 0.762 ms
2 six01-sea4.amazon.com (206.81.80.147) 0.746 ms 0.732 ms 0.715 ms
3 72.21.222.183 (72.21.222.183) 2.657 ms 2.651 ms 2.638 ms
4 72.21.222.179 (72.21.222.179) 2.618 ms 2.604 ms 2.591 ms
5 * * *
6 * * *
7 * * *
Update: The offending incoming packet that causes the RST to be sent
19:58:42.559118 IP (tos 0x0, ttl 57, id 18905, offset 0, flags [DF], proto TCP (6), length 868) 189-81.amazon.com.www > locum.sparklit.com.39491: ., cksum 0x9f6e (correct), 7301:8129(828) ack 212 win 916
0x0000: 4500 0364 49d9 4000 3906 05d7 cfab bd51 E..dI.#.9......Q
0x0010: 4022 21c5 0050 9a43 bbac ea50 0b8d 2730 #"!..P.C...P..'0
0x0020: 5010 0394 9f6e 0000 7c75 a901 cd57 0718 P....n..|u...W..
0x0030: a786 e954 4160 3734 f563 5029 e7ad 48a7 ...TA`74.cP)..H.
0x0040: 34c0 b11b 75a2 a341 c1e6 8aab a03c 31ee 4...u..A.....<1.
0x0050: 1496 c9ef df22 aadc b87e 8431 fc2a dcd6 ....."...~.1.*..
0x0060: e72d 8cf7 aa92 5b12 4923 3f51 50cd 5195 .-....[.I#?QP.Q.
0x0070: 7910 6ce4 0fc0 d63c f115 276b b7e7 5bf7 y.l....<..'k..[.
0x0080: 508e d8fa d655 c5b3 1638 3cd6 6cd1 198c P....U...8<.l...
0x0090: 1c7f 1b7e 59a4 4370 9c87 523d 0ae2 adb4 ...~Y.Cp..R=....
0x00a0: 4d8e 7ad5 7954 c6ac 79e3 9e05 4148 6c97 M.z.yT..y...AHl.
0x00b0: b711 f262 47fa 363f 9d52 bcd4 a58e 177f ...bG.6?.R......
0x00c0: b33b 1033 b530 7351 d8eb 29a9 dbcf 2c6b .;.3.0sQ..)...,k
0x00d0: b161 99e0 3e67 192b 8c9f a735 89ad f886 .a..>g.+...5....
0x00e0: 4d3a ff00 462e b0ad 8dec 8f04 9bdb 9121 M:..F..........!
0x00f0: 4263 0ac4 81c9 18e7 ae6a 1a65 d8db d3ee Bc.......j.e....
0x0100: 3722 b608 cf24 1182 2ba1 b39b 728a f29b 7"...$..+...r...
0x0110: df1e db68 9af5 b69a e51e 5923 2ed0 29fd ...h......Y#..).
0x0120: f0e4 6303 f8bb f4ae ef44 d5e3 bc67 8f70 ..c......D...g.p
0x0130: 5b88 8299 a30d 931e e1c0 38fc 6bca a917 [.........8.k...
0x0140: 7b9d 8a2d 2bb3 5ef7 9e0d 625e c59c d6dc {..-+.^...b^....
0x0150: e778 cd67 5c26 ecd2 a64b 6737 345b 643d .x.g\&...Kg74[d=
0x0160: 6a3d b57e f22f 98d5 455e b5da b546 0c60 j=.~./..E^...F.`
0x0170: 5c51 5281 8a69 4e69 888c af15 0b0a b240 \QR..iNi.......#
0x0180: c540 c334 0101 1935 04b5 6996 a091 7ad0 .#.4...5..i...z.
0x0190: 2676 ba0d 8bbc 30cc 3385 c7f2 a835 ab19 &v....0.3....5..
0x01a0: 2e0b 003a d75b e17b 453a 03b6 070a a7f4 ...:.[.{E:......
0x01b0: a6cf 671e 7270 6b59 ae5e 5f43 28eb 73cd ..g.rpkY.^_C(.s.
0x01c0: 53c2 8f34 9c8e 3e95 d268 fe0f 4864 4661 S..4..>..h..HdFa
0x01d0: 9008 2702 b75e 782d 81e0 0fc2 b3ae bc51 ..'..^x-.......Q
0x01e0: 0c00 e080 477a 9bb6 3b1f 08fc 7efd 943e ....Gz..;...~..>
0x01f0: 26eb ff00 163c 4bad 695e 1b97 51d2 2f6e &....<K.i^..Q./n
0x0200: 4cb6 f35b dca3 7c98 1d46 ec8f a62b c675 L..[..|..F...+.u
0x0210: 4fd9 dfc7 1a4b b2df e812 da63 fe7e 0b2f O....K.....c.~./
0x0220: eb8a fd38 bff1 d055 386f c735 cf5f f8fa ...8...U8o.5._..
0x0230: 7705 44ac 54f6 2723 f2ae d862 2a25 6b1c w.D.T.'#...b*%k.
0x0240: f2a5 06ee 7e6b a7c1 bd79 f2a2 2b1d c3b1 ....~k...y..+...
0x0250: ba5c d759 e03f 849a e787 3564 d6af 2d6d .\.Y.?....5d..-m
0x0260: db4e b7fd d48f 0ca1 8866 1c0e dcd7 db37 .N.......f.....7
0x0270: b2d9 eb2e 4dd6 9767 704f 5692 d949 fcf1 ....M..gpOV..I..
0x0280: 53da 7c3c d0fc 45a3 ea3a 4cf6 3f67 b379 S.|<..E..:L.?g.y
0x0290: a197 cbb5 7311 0dcf 20d6 8f11 2d99 2a94 ....s.......-.*.
0x02a0: 7a1e 69e1 9fda 77c5 7e0d d3ad 74f8 eeac z.i...w.~...t...
0x02b0: e6b3 b641 1c71 df5b 6085 1db7 a907 f3cd ...A.q.[`.......
0x02c0: 7a3e 81fb 6b4c 42ff 0069 6831 4ebd dec6 z>..kLB..ih1N...
0x02d0: e837 fe3a c335 3d9f ec75 e01d 576b 5c47 .7.:.5=..u..Wk\G
0x02e0: ab12 c3a7 f683 8fe9 5a29 fb07 7c31 3f32 ........Z)..|1?2
0x02f0: dbea 81fd 4ea7 2e7f 98ae 37ec 99aa 53e8 ....N.....7...S.
0x0300: cb5a 97ed cfe0 ad1f 4d6b 99f4 bd56 79c1 .Z......Mk...Vy.
0x0310: ff00 8f48 d151 c8ef 8627 15f4 1681 acc5 ...H.Q...'......
0x0320: e21d 0b4e d56d e378 adef add2 e238 e5c6 ...N.m.x.....8..
0x0330: f556 1900 e38c d781 d97e c3bf 0ce0 71f6 .V.......~....q.
0x0340: 9b1d 42ea 31fc 0fa9 cf8f fd0a be80 d2b4 ..B.1...........
0x0350: f834 8d3a d2c2 d13c ab4b 5896 1850 9270 .4.:...<.KX..P.p
0x0360: 8a30 073e .0.>
So we finally figured it out-
It turns out that our router was injecting the RST packets because Netfilter declared the packet invalid. There is a setting that makes netfitler more liberal so I tried enabling it (inet.ipv4.netfilter.ip_conntrack_tcp_be_liberal=1) and the connection is no longer torn down.
However, I still haven't figured out why netfilter declared that packet as invalid. Enabling "ip_conntrack_log_invalid" doesn't cause anything to be printed in the log.
This is a guess. Maybe running some traceroutes to the target target and collecting the hops. Then pinging each of the hops with a 1500 byte packet configured for a 100 count would help identify problems links.
The sender is entitled to send any length packet it likes between 1 and 1460 (in this case, being your apparent MTU). The question is why does your server send the RST?