brighttalk learning to cook- network management recipes - final
TRANSCRIPT
Learning to Cook: Network Management Recipes
https://cbsstlouis.files.wordpress.com/2013/01/kidscooking.jpg
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Mr. White has over fifteen years of experience designing and managing the deployment of Systems Monitoring and Event Management software. Currently, he is serving as the Operational Readiness Leader for a Fortune 50 Enterprise. Mr. White has also held positions including Executive Architect at IBM, leader of the Monitoring and Event Management organization at Nationwide Insurance and owner of a Service Management Consultancy developing solutions for a wide variety of organizations, including the Mexican Secretaría de Hacienda y Crédito Público, Telmex, Wal-Mart of Mexico, JP Morgan Chase, Nationwide Insurance and the US Navy Facilities and Engineering Command.
Andrew White Long Time System Management Expert UX Evangelist
For those of you who are sleeping right now…
This topic isn’t going to help much. SORRY :(
http://weheartit.com/entry/12433848
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Ground rules for this session… • If you can’t tell if I am trying to be funny…
– GO AHEAD AND LAUGH! • Feel free to text, tweet, yammer, or whatever.
Use • If you have a question, no need to wait until
the end. Just interrupt me. Seriously… I don’t mind.
I have a lot of experience leading Systems and Event Management teams
Latency I am here today to share some of what I have learned about
User Experience
And more importantly, I am here today to talk about
What do I mean by latency and user experience?
Definitions:
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La�ten�cy – [LEYT-n-see] -noun, plural -cies 1. The state of being latent 2. The time that elapses between a stimulus and the
response to it 3. The state of being not yet evident or active
http://www.flickr.com/photos/25822731@N02/4644128723/
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Ex�pe�ri�ence – [ik-SPEER-ee-uh’ns] -noun 1. The apprehension of an object, thought, or emotion through
the senses or mind 2. Direct personal participation or observation; actual knowledge
or contact 3. A particular incident, feeling, etc., that a person has
undergone -verb 4. To be emotionally or aesthetically moved by; to feel 5. To learn by perceiving, understanding, or remembering
http://www.flickr.com/photos/51035626620@N01/170061976/sizes/l/in/photostream/
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When you put them together we get: The ultimate measure of success for any system is the perception of its performance. The less interactive a system becomes the more likely its performance will be perceived to be poor.
Latency is the mother of inactivity!
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The Two Dimensions of Latency… Internal Latency vs. External Latency
Actual Latency vs. Perceived Latency
This is what user experience is all about
In other words: Perceived = Fn(Internal+External)Variation )
We need to recognize when we have problems to solve
Maybe. Let me show you why this is important…
Is 5 seconds really bad?
Start…
Start…
Observed Maximum:
90th Percentile: 5.44 seconds…
15.4 seconds…
Start…
Start…
Observed Maximum:
90th Percentile: DONE! 5.44 seconds…
15.4 seconds…
Start…
Start…
Observed Maximum:
90th Percentile: DONE!
DONE!
5.44 seconds…
15.4 seconds…
If you were the one on the phone with one of those customers…
how would you fill that silence?
Why does any of this matter?
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No complaint… is more common than that of a scarcity of money-Adam Smith, Wealth of Nations
*Among adults who accessed the internet with a mobile phone in the past 12 months (n=1,001) – Gomez Mobile Web Experience Survey conducted by Equation Research
58% of mobile phone users expect websites to load as quickly, almost as quickly or faster on their mobile phone, compared to the computer they use at home*
http://www.flickr.com/photos/lucianbickerton/3858380291/sizes/l/
*Among adults who accessed the internet with a mobile phone in the past 12 months (n=1,001) – Gomez Mobile Web Experience Survey conducted by Equation Research
60% of mobile web users have had a problem in the past year when accessing a website on their phone*
http://www.flickr.com/photos/rickyromero/1357938629/sizes/l/
*Among adults who accessed the internet with a mobile phone in the past 12 months (n=602) – Gomez Mobile Web Experience Survey conducted by Equation Research
Slow load time was the number on issue, experience by almost 75% of them*
http://bighugelabs.com/onblack.php?id=2497744197&size=large
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Our Problem Statement:
The business needs to reliably reach its customers and users regardless of where they may be located. Latency
forces close geographic proximity of the components and limits the quality of service provided to
geographically distributed customers.
If the users can’t use it, it doesn’t work.
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Our Constraints At the same time, there are a few inescapable facts we face: 1. Today’s users demand reliable systems to do their work 2. IT systems will mirror the complexity of the businesses
they support 3. Our environments must be massive to handle the workload 4. Business continuity requires geographic diversity in our
deployment locations 5. The speed of light isn’t changing any time soon
When all of these happen at the same time…
Ug…
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Question
Is there a better way to figure out what monitoring would help?
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Itemize the existing monitors
Brainstorm potential gaps
to fillDeploy new
monitors
Identify the potential
risks
Itemize the existing monitors
Determine if which
gaps exist
Fill the monitoring
gaps
Current Approach
Proposed Approach
Picking Better Monitors
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What Do You Want To Accomplish? Your monitoring should help you answer: • How will we know if the users are getting the experience
they are expecting? • How much capacity do we need during normal and peak
times to ensure user expectations are met? • How quickly can the provider we select ramp up to meet
our needs if we find that the service is underperforming? • How fast do we need to be able to access additional
capacity once it is ready for us?
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Composite Applications
Site ContentSearch
SessionInformation
User Login& Identity Mgmt
Content MgmtSystem
Social NetworkWidgets
Site Tracking& Analytics
Banner Ads & Revenue Generators
Multimedia &CDN Content
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Composite Applications Are Everywhere
• ATG (Oracle) – Shopping Cart • Estara – Click to Chat • Twitter Widget – Social Networking • Gigya – Social Networking • Google Maps API – GeoLocation • Facebook Widget – Social Networking • Google Analyics – User Tracking
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Seeing Is Believing Real User Monitoring Would Report 94ms Response Time.
The page seemed “done” to me
1.2 seconds later
The time spent rendering represented 93% of the
user experienced latency
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The Same Old Problem
CorporateLANs & VPNs
ISPConnection
DNS & InternetServices
Content MgmtSystem
Social NetworkWidgets
Site Tracking& Analytics
Banner Ads & Revenue Generators
Multimedia &CDN Content
Home Wireless& Broadband
Mobile Broadband
Is It My Data Center?• Configuration errors• Application design issues• Code defects• Insufficient infrastructure• Oversubscription Issues• Poor routing optimization• Low cache hit rate
Is It a Service Provider Problem?• Non-optimized mobile content• Bad performance under load• Blocking content delivery• Incorrect geo-targeted content
Is it an ISP Problem?• Peering problems• ISP Outages Is it My Code or a Browser Problem?
• Missing content• Poorly performing JavaScript• Inconsistent CSS rendering• Browser/device incompatibility• Page size too big• Conflicting HTML tag support• Too many objects• Content not optimized for device
The Cloud
Distributed
Database
Mainframe
Network
Middleware
Storage
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Cognitive Dissonance
Corporate LANs & VPNs
Distributed
Database
Mainframe
Network
Middleware
Storage
ISP Connection
DNS & Internet Services
Content Mgmt System
Social Network Widgets
Site Tracking & Analytics
Banner Ads & Revenue Generators
Multimedia & CDN Content
Home Wireless & Broadband
Mobile Broadband
The Part You Control
The Part They Experience
…meanwhile the user is NOT happy
All our systems look great,
SLA’s are being met…
You Have More Control Here Than
You Think
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Gaining Perspective Requires Balance
Packet Capture
Synthetic Transactions
Client Monitoring
Client Monitoring
Synthetic Transactions
Server Probe
1. Client to the Server2. Server to the Client3. “3rd Party” Vantage Point4. Synthetic Transactions
Four Perspectives of User Experience
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Why Multiple Perspectives? Know Your Customer: • What they do?
§ Customers care about completing tasks NOT whether the homepage is available
• Where they do it from? § Your customers don’t live in the cloud, test from their perspective
• When they do it? § Test at peak and normal traffic levels, to find all the problems
• What expectations do customers have? § Is 5 seconds fast enough or does it have to be quicker?
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What Does Good Monitoring Look Like?
CorporateLANs & VPNs
Load Balancer
Load Balancer
Firewall
Switch
Web Server Farm
Database
Data PowerMainframe
Middleware
Load Balancer
1. System Availability 2. Operating System Performance 3. Hardware Monitoring 4. Service/Daemon and Process Availability 5. Error Logs 6. Application Resource KPIs 7. End-to-End Transactions 8. Point of Failure Transactions 9. Fail-Over Success 10. “Activity Monitors” and “Reverse Hockey Stick”
Elements of Good Monitoring 32 4 5 61
7
8
9 10
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When decisions are not made based on information, it’s called gambling.
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Finding Metrics That Matter § Will the metric be used in a report? If so, which one? How is it used in the report? § Will the metric be used in a dashboard? If so, which one? How will it be used? § What action(s) will be taken if an alert is generated? Who are the actors? Will a ticket
be generated? If so, what severity? § How often is this event likely to occur? What is the impact if the event occurs? What
is the likelihood it can be detected by monitoring? § Will the metric help identify the source of a problem? Is it a coincident / symptomatic
indicator? § Is the metric always associated with a single problem? Could this metric become a
false indicator? § What is the impact if this goes undetected? § What is the lifespan for this metric? What is the potential for changes that may
reduce the efficacy of the metric?
Evaluating the Effectiveness of a Metric
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Watch your words
737-900ER 747-400ER
Maximum Number of Passengers
215 524
Maximum Crusing Speed (mph) 511 570
A 737 and a 747 both travel around 500 mph but the 747 carries twice as many people. Would you say it is twice as fast?
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What Matters Most?
Dr. Lee Goldman
Cook County Hospital, Chicago, IL
§ Is the patient feeling unstable angina?
§ Is there fluid in the patient’s lungs? § Is the patient’s systolic blood
pressure below 100?#
The Goldman Algorithm
Prediction of Patients Expected to Have a Heart Attack Within 72 Hours
0
20
40
60
80
100
Traditional Techniques Goldman Algorithm
By paying attention to what really matters, Dr. Goldman improved the “false negatives” by 20
percentage points and eliminated the “false positives” altogether.
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• Server Metrics – Server Response Time – Server Connection Time – Refused Session Percentage – Unresponsive Session Percentage
• Network Metrics – Network Round Trip Time – Retransmission Delay – Effective Network Round Trip Time – Network Connection Time
• Application Metrics – Total Transaction Time – Data Transfer Time
Really Helpful KPIs
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Beware of Averages 75th
Percentile50th
Percentile25th
Percentile
0.5 0.7 0.9 1.8 2.5 2.5 2.6 2.9 3.3 3.5
Average
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Your Mission… In addition to monitoring for system availability, we are here to help manage latency.
The Recipe:
1. Continually map, monitor, and categorize all sources of latency
2. Help identify and remove all sources that are found
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The Critical Path of Performance
Browser Workstation OS
Workstation Hardware Client LAN Corporate
WAN Datacenter
LAN Etc.
Web Server Web Server OS
Web Server Hardware
Datacenter LAN
Middleware Server
Hardware Middleware Server OS
Middleware Application Etc.
Database Server
Database Server OS
Database Server HBA
SAN Fabric Switch
Array Hardware
Array Controller
Hardware Cache
Disk Drives Etc.
Client Node
Middleware
Database
Starting the journey…
SNMP
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MIBs and OIDs root
iso (1)
org (3)
dod (6)
Internet (1)
Interfaces (2) IP (4) System (1)
ifOperStatus = ..1.3.6.1.2.1.2.2.1.8.0
MIB-2 (1)
Directory (1) Experimental (3) Mgmt (2) Private (4)
Juniper (2636) Cisco (9) Apple (63) Microsoft (311)
Port OperStatus = .1.3.6.1.4.1.9.5.1.4.1.1.6.0 Functionally the same
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MIBs and OIDs root
iso (1)
org (3)
dod (6)
Internet (1)
Interfaces (2) IP (4) System (1)
MIB-2 (1)
Directory (1) Experimental (3) Mgmt (2) Private (4)
Juniper (2636) Cisco (9) Apple (63) Microsoft (311)
Port Index = .1.3.6.1.4.1.9.5.1.4.1.1.4.0 A MIB is the set of OIDs for a defining a set of information in the database
Port Type = .1.3.6.1.4.1.9.5.1.4.1.1.5.0 Port OperStatus = .1.3.6.1.4.1.9.5.1.4.1.1.6.0 Port IfIndex = .1.3.6.1.4.1.9.5.1.4.1.1.11.0
portMacControlUnknownProtocolFrames = .1.3.6.1.4.1.9.5.1.4.1.1.21.0
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RMON
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RMON is “Flow-Based” Monitoring
RMON v1 (RFC 2819) • Statistics: real-time LAN statistics e.g. utilization,
collisions, CRC errors • History: history of selected statistics • Alarm: definitions for RMON SNMP traps to be
sent when statistics exceed defined thresholds • Hosts: host specific LAN statistics e.g. bytes
sent/received, frames sent/received • Hosts top N: record of N most active
connections over a given time period • Matrix: the sent-received traffic matrix between
systems • Filter: defines packet data patterns of interest e.g.
MAC address or TCP port • Capture: collect and forward packets matching
the Filter • Event: send alerts (SNMP traps) for the Alarm
group • Token Ring: extensions specific to Token Ring
RMON v2 (RFC 4502) • Protocol Directory: list of protocols the probe can
monitor • Protocol Distribution: traffic statistics for each
protocol • Address Map: maps network-layer (IP) to MAC-
layer addresses • Network-Layer Host: layer 3 traffic statistics, per
each host • Network-Layer Matrix: layer 3 traffic statistics, per
source/destination pairs of hosts • Application-Layer Host: traffic statistics by
application protocol, per host • Application-Layer Matrix: traffic statistics by
application protocol, per source/destination pairs of hosts
• User History: periodic samples of user-specified variables
• Probe Configuration: remote configure of probes • RMON Conformance: requirements for RMON2
MIB conformance
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The RMON MIBs root
iso (1)
org (3)
dod (6)
Internet (1)
Interfaces (2) IP (4) System (1)
MIB-2 (1)
Directory (1) Experimental (3) Mgmt (2) Private (4)
RMON (16)
RMON data is stored in a MIB and can be collected using SNMP
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MIBs and OIDs root
iso (1)
org (3)
dod (6)
Internet (1)
Interfaces (2) IP (4) System (1)
MIB-2 (1)
Directory (1) Experimental (3) Mgmt (2) Private (4)
RMON (16)
rmonEventsV2 statistics history alarm hosts hostTopN matrix filter Capture Event tokenRing protocolDir protocolDist addressMao nlHost nlMatrix alHost alMatrix usrHistory probeConfig rmonConformance mediaIndependentStats switchRMON interfaceTopNMIB hcAlarmMIB
= .1.3.6.1.2.1.16.0 = .1.3.6.1.2.1.16.1.0 = .1.3.6.1.2.1.16.2.0 = .1.3.6.1.2.1.16.3.0 = .1.3.6.1.2.1.16.4.0 = .1.3.6.1.2.1.16.5.0 = .1.3.6.1.2.1.16.6.0 = .1.3.6.1.2.1.16.7.0 = .1.3.6.1.2.1.16.8.0 = .1.3.6.1.2.1.16.9.0 = .1.3.6.1.2.1.16.10.0 = .1.3.6.1.2.1.16.11.0 = .1.3.6.1.2.1.16.12.0 = .1.3.6.1.2.1.16.13.0 = .1.3.6.1.2.1.16.14.0 = .1.3.6.1.2.1.16.15.0 = .1.3.6.1.2.1.16.16.0 = .1.3.6.1.2.1.16.17.0 = .1.3.6.1.2.1.16.18.0 = .1.3.6.1.2.1.16.19.0 = .1.3.6.1.2.1.16.20.0 = .1.3.6.1.2.1.16.21.0 = .1.3.6.1.2.1.16.22.0 = .1.3.6.1.2.1.16.23.0 = .1.3.6.1.2.1.16.24.0
All this information lives in just one table and most people don’t know about it!
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Setting Thresholds
Falling Threshold
Rising Threshold
Sample Interval
Policy Activations
Netflow
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How we view the network
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How our applications view it
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What a Flow Record Looks Like
http://www.cisco.com/c/en/us/td/docs/ios/fnetflow/configuration/guide/12_2sr/fnf_12_2_sr_book/fnetflow_overview.html
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One record, multiple uses
http://www.cisco.com/c/en/us/td/docs/ios/fnetflow/configuration/guide/12_2sr/fnf_12_2_sr_book/fnetflow_overview.html
Packet Inspection
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The Progression
SNMP
Granularity
Acc
urac
y
RMON
Netflow
Packet Inspection
That is great but we need more…
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Shallow vs Deep Packet Inspection
SPI is very focused on header information from OSI Layers 3 & 4 (IP, TCP, UDP, etc.) DPI processes header and datagram information (HTTP, SQL, SIP, etc.)
IP Header TCP Header GET /userLogin.jsp HTTP/1.1 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A
Shallow Packet Inspection (SPI)
Deep Packet Inspection (DPI)
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Shallow Packet Inspection
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Degraded Threshold – The point at which users will complain about poor performance
Excessive Threshold – The point at which users will
stop using the application due to poor performance
Two Different Thresholds
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3. Compare network latency across sites
2. Prove the value of a server upgrade 1. Document the results of QoS changes
Validating Changes
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Solving Problems
Pervasiveness: The problem is effecting user across your network
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Troubleshooting VoIP
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Don’t Commit a Felony
Putting it all together
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Using Indices • Network Congestion Index
• Packet Loss SLAs
NCI = (Packets/sec + Avg Payload) * (Avg Latency + Avg Bandwidth)
App Owner Controlled Network Controlled
bps < min(rwin/rtt, MSS/(rtt*sqrt(loss))) For example, to achieve a gigabit per second with TCP on a coast-to-coast path (rtt = 40 msec), with 1500 byte packets, the loss rate can not exceed 8.5x10^-8! If the loss rate was even 0.1% (far better than most SLAs), TCP would be limited to just over 9 Mbps. [Note that large packet sizes help. If packets were n times larger, the same throughput could be achieved with n^2 times as much packet loss.]
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Let’s keep the conversation going…
ReverendDrew
SystemsManagementZen.Wordpress.com
systemsmanagementzen.wordpress.com/feed/
@SystemsMgmtZen
ReverendDrew
614-306-3434