This document discusses optimizing cloud applications in RightScale. It covers topics like 3-tier application architecture, vertical and horizontal scaling, monitoring with RightScale and New Relic RPM, optimizing database performance, and load testing. Key points include how RightScale supports monitoring through server templates, collected data, and cluster graphs, and how New Relic RPM provides application performance analytics. It also discusses optimizing databases by configuring for instance size, identifying bottlenecks, and monitoring performance metrics and queries.
10. 10#
Server arrays provide horizontal scaling
• The array scales up or down based on performance votes
• Tags allow scaling on an arbitrary decision set
• Decision threshold controls reaction time
• Sleep time allows new resources to have an impact
• Scaling can be time dependent
• Detailed setup instructions: http://bit.ly/c1oLr2
• Fast response to changes in load conditions using alerts
• Allocation of servers to availability zones based on weights
• Deployment-based so configuration is consistent
• Arrays can be pre-scaled to support anticipated demand
Real Cloud Experience. Shared.
11. 11
Optimizing Your Cloud Applications in RightScale
Monitoring & Cluster Graphs
with RightScale
13. 13#
Cluster monitoring
• Individual graphs
• Good for a dozen servers
• Displays all standard graphs with full detail
• Stacked graphs
• Displays the contribution of many servers to a total
• Great to see the sum and variability of activity in a cluster
• Difficult to make out individual servers
• Examples: requests/sec, cpu busy cycles, I/O bytes/sec
• Heat maps
• Displays a bar for each server
• Great to see uneven distribution across servers
• Great to quickly spot performance problems across many servers
• Difficult to read absolute values or see the total cluster activity
Real Cloud Experience. Shared.
14. 14#
Cluster monitoring architecture
• Architecture
• Monitoring front-end servers
pull data from storage servers
• Up to 100 servers on one graph
(to be increased)
monitoring monitoring
storage front-end
servers servers
your servers
Real Cloud Experience. Shared.
15. 15#
Cluster monitoring
• Current cluster monitoring: one graph per server
Real Cloud Experience. Shared.
16. 16#
Stacked graphs
• Each color band shows contribution of one server
• Servers are stacked on top of one another
Real Cloud Experience. Shared.
17. 17#
Heat maps
• Each horizontal strip shows one server
• The color shows how “hot” the server is running
Real Cloud Experience. Shared.
22. 22#
New Relic RPM
• Direct access from RightScale dashboard
Real Cloud Experience. Shared.
23. 23#
New Relic RPM
• Historical statistics over a period of time
Real Cloud Experience. Shared.
24. 24#
New Relic RPM
• Distribution of the most time consuming requests
Real Cloud Experience. Shared.
25. 25#
New Relic RPM
• Statistics about response times from different countries
Real Cloud Experience. Shared.
26. 26#
New Relic RPM
• Detailed response times by browser
Real Cloud Experience. Shared.
27. 27#
New Relic RPM – 2 Examples
• An expensive query
• The N+1 query problem
Real Cloud Experience. Shared.
28. 28
Optimizing Your Cloud Applications in RightScale
Optimizing Database Performance
29. 29#
Optimizing DB performance
• RightScale MySQL ServerTemplates
• Configuration files tailored to instance size
• innodb_buffer_pool_size
• key_buffer_size
• thread_size
• sort_buffer_size
• The never ending task of identifying current bottlenecks
• Disk seeks
• Performance of disk operations
• Scale up when working set cannot fit in memory – avoid active swapping
• Constant monitoring of performance graphs, logs and query
• Schema considerations
Real Cloud Experience. Shared.
30. 30#
Schema considerations
• Lookups need to be indexed
• Sorting requires an index
• Joins need to be done on indices
• Become slower as tables grow
• Compounded indices should be used consistently
• Do not abuse indices
• Each index requires a disk write
• Compact tables if they become fragmented
• Deleted rows do not remove the corresponding index entries
Real Cloud Experience. Shared.
31. 31#
Monitoring DB performance
• Standard collectd statistics
• User vs wait time (disk operations)
• Performance of disk operations
• Scale up when working set cannot fit in memory
• MySQL collectd plugin
• Monitor INSERT, SELECT, UPDATE operations
• The breakdown of read operations can indicate missing indices
• Monitoring /var/log/mysqlslow.log file
• Identify slow queries
• Use MySQL EXPLAIN command to identify query plan
Real Cloud Experience. Shared.
32. 32#
MySQL Collectd Plugin
• Uses MySQL SHOW STATUS command to collect statistics
• A large set of counters that are divided into 10 categories
• Connections
• IO Requests
• Select Rates
• Read Rates
• Key Rates
• Commands Rates
• Query Cache
• Tables
• Memory
• Misc.
Real Cloud Experience. Shared.
33. 33#
MySQL Collectd Plugin
• Uses MySQL SHOW STATUS command to collect statistics
Real Cloud Experience. Shared.
35. 35#
MySQL performance depends on locality
• Wait time should be minimum when working set fits in memory
• Performance degrades once wait time is significant
wait time insignificant
user time dominates
Real Cloud Experience. Shared.
36. 36#
MySQL reads graphs
• Read-random-next represents a table scan
• Read-next represents an index scan
Real Cloud Experience. Shared.
38. 38#
Load testing using httperf
• RightScale provides ServerTemplates in the marketplace
• https://my.rightscale.com/library/server_templates/Httperf-Load-Tester/24714
• Tutorial on httperf setup and configuration
• http://support.rightscale.com/03-Tutorials/02-AWS/E2E_Examples/E2E_Gaming_Deployment/Adding_Httperf_Load_Tester
Real Cloud Experience. Shared.
Notas del editor
The cluster monitoring is very powerful in that it provides different types of views into the operation of large clusters of servers
The cluster monitoring is very powerful in that it provides different types of views into the operation of large clusters of servers
The architecture behind the cluster monitoring is rather extensiveCustomer (i.e. your) servers send monitoring data every 20 seconds to our serversThe data points are cached in-memory on those servers and flushed to disk periodicallyCluster monitoring graphs are produced on separate front-end servers, which pull the data from over 100 monitoring storage serversThe graphs are produced using rrdtool and auto-refresh
Walk through ofhow it works: in any deployment, go to the monitoring tab select servers select metric to plot familiar controls to switch time period and graph size displays one graph per server, here core1.rightscale.com through core8.rightscale.com in this example the graphs show cpu utilization for the past week, where blue is busy time and green is idle
Individual graphs only work for so many servers, they also don’t show what is happening as an aggregateStacked graphs stack the contribution of each server on top of one anotherWalk through what the graph shows
Stacked graphs are great to see the aggregate, but it is often difficult to see abnormal server behaviorHeat maps show many servers on one graph by plotting one horizontal bar per serverThe time axis is the same for all servers and it is shown at the bottom of the graphThe color of the bar shows the value of the metric for the serverWalk through the graphIt’s easy to see that there are 6 servers sharing the load, and two servers that are different
At scale this is how all this looks and comes togetherThis example is real, it shows an incident we had with our monitoring cluster a few months agoThis heat map shows 100 servers out of one of our monitoring clusters (we want to be vague here…)When there are more than 100 servers, the heat map shows a sampling of 100Describe the sampling: most recently launched, longest running, some of each server template, rest randomStory:This heat map plots I/O wait for our monitoring servers on a day where we suddenly received a number of alerts for a few serversThe heap map shows these servers clearly as red bands starting between 7am and 8amSo we could clearly see that something was going on with a small number of servers and that it started more or less at the same time on all themTo see what happened in aggregate, we can switch graph type…
This shows the same incident as on the previous slide, but with a timescale of a weekIt shows the number of servers handled by each monitoring server, i.e. each color bar shows one serverIt is easy to see that some customer launched a large number of servers right at the time the overload beganFurther investigation showed that due to a bug these servers were allocated unevenly across the cluster causing the overload’