© 2009 IBM Corporation RESEARCH Peeking into Cloud for better Application Manageability Sambit Sahu IBM Research

RESEARCH © 2009 IBM Corporation Cloud Virtualizes Resources (cpu, mem, network, storage..)  Cloud simplifies resource access through virtualization –User can get easy and inexpensive access to virtualized resources –Lower entry barrier with pay as you use –On-demand elastic resource access  Implication on application management hosted on Cloud –Decoupling between underlying resources and application management layer –May not even have ability or control over application placements or deployments –Typically Cloud provider and Service Provider or Users belong to different organizations  Challenges –How to efficiently manage applications where –No physical resource access or control due to virtualization layer –No or limited visibility on “what-is-going-on” in the physical resource level –What support or primitives need to be made available to facilitate efficient problem resolution? Service Y Service X server, network, storage, middleware resources Hypervisor Layer Cloud Resource Provision Layer Trusted Virtual Domains Application Management Layer Application 1 Application 2

RESEARCH © 2009 IBM Corporation Analysis of Open Forum Message Threads of a Large Cloud Provider  Analyzed open forum message threads for problem classification and resolution process understanding –Collected messages posted on a Cloud open forum over last three years –About 8000 unique message threads with about messages –Analyzed messages over 3 months period and random sampling of messages over rest of the period –Major problem categories and classifications –Nature of resolutions  Objective –Understand top problems and solutions provided by the cloud provider –Understand impact of information hiding due to virtualization on problem resolution –Determine if any information and/or tooling would help service providers and users for efficient problem resolution/isolation

RESEARCH © 2009 IBM Corporation Common Symptoms and stage based problem classification Provisioning stage – least problems encountered Most management & third party target this Running stage – most problems encountered Terminating stage – surprisingly second largest contributor of problems Instance reachability problems Management of instance depends on instance Instance unbootable Virtualization mask failures Connectivity issues Infrastructure network problems, firewall rules,… Component: Virtual infrastructure issues Unable to disconnect/connect virtual infrastructure Fig 1: Commonly Encountered SymptomsFig 2: State based problem classification

RESEARCH © 2009 IBM Corporation Some Problem Resolution Statistics Figure 4: Resolution Time 60% problems were resolved in a day Additional 20% problems took more than additional 3 days Figure 3: About 97 administrators responding to users via open forum where few administrators answered majority of the problems (20 admin accounted for more than 80%)

RESEARCH © 2009 IBM Corporation Multiple problems manifest with same symptoms Fig 3: Same symptoms for different set of problems Level of support and solutions for resolving problem Instance Reboot Host Reboot Software Fixes Manual modification of infrastructure state Manual modification of network configuration Firewall Router configuration Typical steps taken to resolve/fix the problems

RESEARCH © 2009 IBM Corporation Summary  Layering in a Cloud (virtualization of physical resources) hides crucial information away from users –Multiple problems manifest as same symptoms  Issues –What information can and should be shared between cloud provider and cloud users or service providers? –How to achieve this peeking without compromising security issues?  Some initial thoughts on information unlayering –Topology view –Dependent resource health –Resource logs –Dependent access policies - …