Transcript Document
PlanetLab Architecture Larry Peterson Princeton University Issues • Multiple VM Types – Linux vservers, Xen domains • Federation – EU, Japan, China • Resource Allocation – Policy, markets • Infrastructure Services – Delegation Need to define the PlanetLab Architecture Key Architectural Ideas • Distributed virtualization – slice = set of virtual machines • Unbundled management – infrastructure services run in their own slice • Chain of responsibility – account for behavior of third-party software – manage trust relationships Trust Relationships Princeton Berkeley Washington MIT Brown CMU NYU ETH Harvard HP Labs Intel NEC Labs Purdue UCSD SICS Cambridge Cornell … Trusted Intermediary NxN (PLC) princeton_codeen nyu_d cornell_beehive att_mcash cmu_esm harvard_ice hplabs_donutlab idsl_psepr irb_phi paris6_landmarks mit_dht mcgill_card huji_ender arizona_stork ucb_bamboo ucsd_share umd_scriptroute … Principals • Node Owners – host one or more nodes (retain ultimate control) – selects an MA and approves of one or more SAs • Service Providers (Developers) – implements and deploys network services – responsible for the service’s behavior • Management Authority (MA) – installs an maintains software on nodes – creates VMs and monitors their behavior • Slice Authority (SA) – registers service providers – creates slices and binds them to responsible provider Trust Relationships (1) Owner trusts MA to map network activity to responsible slice MA (2) Owner trusts SA to map slice to responsible providers 6 1 (3) Provider trusts SA to create VMs on its behalf 4 Owner Provider 2 (5) SA trusts provider to deploy responsible services 3 5 SA (4) Provider trusts MA to provide working VMs & not falsely accuse it (6) MA trusts owner to keep nodes physically secure Architectural Elements MA Node Owner slice database Owner VM NM + VMM SCS VM SA node database Service Provider Narrow Waist • Name space for slices < slice_authority, slice_name > • Node Manager Interface rspec = < vm_type = linux_vserver, cpu_share = 32, mem_limit - 128MB, disk_quota = 5GB, base_rate = 1Kbps, burst_rate = 100Mbps, sustained_rate = 1.5Mbps > Node Boot/Install Process Node Boot Manager PLC Boot Server 1. Boots from BootCD (Linux loaded) 2. Hardware initialized 3. Read network config . from floppy 4. Contact PLC (MA) 6. Execute boot mgr 5. Send boot manager 7. Node key read into memory from floppy 8. Invoke Boot API 9. Verify node key, send current node state 10. State = “install”, run installer 11. Update node state via Boot API 13. Chain-boot node (no restart) 14. Node booted 12. Verify node key, change state to “boot” PlanetFlow • Logs every outbound IP flow on every node – accesses ulogd via Proper – retrieves packet headers, timestamps, context ids (batched) – used to audit traffic • Aggregated and archived at PLC Chain of Responsibility Join Request PI submits Consortium paperwork and requests to join PI Activated PLC verifies PI, activates account, enables site (logged) User Activated Users create accounts with keys, PI activates accounts (logged) Slice Created PI creates slice and assigns users to it (logged) Nodes Added to Slices Slice Traffic Logged Traffic Logs Centrally Stored Users add nodes to their slice (logged) Experiments run on nodes and generate traffic (logged by Netflow) PLC periodically pulls traffic logs from nodes Network Activity Slice Responsible Users & PI Slice Creation . . . PI SliceCreate( ) SliceUsersAdd( ) User SliceNodesAdd( ) SliceAttributeSet( ) SliceInstantiate( ) PLC (SA) SliceGetAll( ) slices.xml NM VM VM … VM VMM . . . Slice Creation . . . PI SliverCreate(ticket) SliceCreate( ) SliceUsersAdd( ) User PLC (SA) NM VM VM … VM SliceAttributeSet( ) SliceGetTicket( ) VMM . . . (distribute ticket to slice creation service) Brokerage Service . . . PI rcap = PoolCreate(ticket) SliceCreate( ) SliceUsersAdd( ) Broker PLC (SA) NM VM VM … VM SliceAttributeSet( ) SliceGetTicket( ) VMM . . . (distribute ticket to brokerage service) Brokerage Service (cont) . . . PoolSplit(rcap, slice, rspec) PLC (SA) User BuyResources( ) NM VM VM VM … VM VMM Broker . . . (broker contacts relevant nodes) Policy Proposals • Suspend a site’s slices while a its nodes are down • Resource allocation to – brokerage services – long-running services • Encourage measurement experiments via ScriptRoute – lower scheduling latency for select slices • Distinguish PL versus non-PL traffic – remove per-node burst limits – replace with sustained rate caps – limit slices to 5GB/day to non-PL destinations (with exceptions)