shaun de witt, stfc maciej brzeźniak, psnc martin hellmich, cern federating grid and cloud storage...

Shaun de Witt, STFCMaciej Brzeźniak, PSNCMartin Hellmich, CERN

Federating Grid and Cloud Storage in EUDAT

International Symposium on Grids and Clouds 2014,

23-28 March 2014

Agenda• Introduction

• …

• …

• …

• Test results

• Future work

3rd EUDAT Technical meeting in Bologna 7th February 2013

Introduction• We present and analyze the results

of Grid and Cloud Storage integration

• In EUDAT we used:– iRODS as Grid Storage federation mechanism

– OpenStack Swift as scalable object storage solution

• Scope:– Proof of concept

– Pilot OpenStack Swift installation in PSNC

– Production iRODS servers in PSNC (Poznan) and EPCC (Edinburgh)

3rd EUDAT Technuical meeting in Bologna 7th February 2013

EUDAT project introduction• pan-European Data Storage & mgmt infrastructure

• Long term data preservation:

• Storage safety, availability – replication, integrity control

• Data Accessibility – visibility, possibility to refer over years

3rd EUDAT Technuical meeting in Bologna 7th February 2013

• Partners: data center & communities:

EUDAT challenges:

3rd EUDAT Technuical meeting in Bologna 7th February 2013

• Federate heterogeneous data management systems:

• dCache, AFS, DMF, GPFS, SAM-FS

• File systems, HSMs, file servers

• Object Storage systems (!)

while ensuring:

• Performance, scalability,

• Data safety, durability, HA, fail-over

• Unique access, Federation transparency,

• Flexibility (rule engine)

• Implement the core services:

• safe and long-term storage: B2SAFE,

• efficient analysis: B2STAGE,

• easy deposit & sharing: B2SHARE,

• Data & meta-data exploration: B2FIND.

Picture showing various storagesystems federated under iRODS

EUDAT CDI domain of registered data:

Grid – Cloud storage integration

• Need to integrate Grids and Cloud/Object storage• Grids get another, cost-effective, scalable backend

• Many institutions and initiativesare testing & using in production object storage including

• Most Cloud Storage use Object Storage concept

• Object Storage solutions have limited supportfor federation that is well addressed in Grids

• In EUDAT we integrated:• object storage system – OpenStack Swift

• iRODS servers and federations

3rd EUDAT Technuical meeting in Bologna 7th February 2013

Context: Object Storage Concept

• The concept enables building low-cost, scalable, efficient storage:• Within data centre

• DR / distributed configurations

• Reliability thanks to redundancy of components:• Many cost-efficient storage servers w/ disk drives (12-60

HDD/SSD)

• Typical (cheap) network: 1/10 Gbit Ethernet

• Limitations of traditional appraoches:• High investment cost and maintenance

• Vendor lock-in, Closed architecture, Limited scalability

• Slow adoption of new technologies than in commodity market

Context: Object Storage importance• Many institutions and initiatives

(DCs, NRENs, companies, R&D projects)are testing & using in production object storage including:• Open source / private cloud:

• Open Stack Swift

• Ceph / RADOS

• Sheepdog, Scality…

• Commercial:• Amazon S3, RackSpace Cloud Files…

• MS Azzure Object Storage…

• Most promising open source: Open Stack Swift & Ceph

Object Storage: Architectures

OpenStack Swift

User Apps

Load balancer

ProxyNode

ProxyNode

ProxyNode

StorageNode

StorageNode

StorageNode

StorageNode

StorageNode

UploadDownload

CEPH

LibRados

RadosGW RBD CephFS

APP HOST / VM Client

Rados

MDS

MDS.1

MDS.n

......

MONs

MON.1

MON.n

......

OSDs

OSD.1

OSD.n

......

Object Storage: concepts:

OpenStack Swift Ring

Source:The Riak Project

Source:http://www.sebastien-han.fr/blog/2012/12/07/ceph-2-speed-storage-with-crush/

Ceph’s map

• No meta-data lookups, no meta-data DB!, data placement/location computed!

• Swift: Ring: represents the space of all possible computed hash values divided in equivalent parts (partitions); partitions are spread across storage nodes

• Ceph: CRUSH map: list of storage devs, failure domain hierarchy (e.g., device, host, rack, row, room) and rules for traversing the hierarchy when storing data.

Object Storage concepts: no DB lookups!

OpenStack Swift Ring

Source:The Riak Project

Source:http://www.sebastien-han.fr/blog/2012/12/07/ceph-2-speed-storage-with-crush/

Ceph’s map

• No meta-data lookups, no meta-data DB!, data placement/location computed!

• Swift: Ring: represents the space of all possible computed hash values divided in equivalent parts (partitions); partitions are spread across storage nodes

• Ceph: CRUSH map: list of storage devs, failure domain hierarchy (e.g., device, host, rack, row, room) and rules for traversing the hierarchy when storing data.

Grid – Cloud storage integration

• Most cloud/object storage solutions expose:• S3 interface

• Other native interfaces: OSS: Swift; Ceph: RADOS

• S3 (by Amazon) is de facto standard in cloud storage:• Many PetaBytes, Global systems

• Vendors use it (e.g. Dropbox) or provides it

• Large take up

• Similar concepts:• CDMI: Cloud Data Management Interface –

SNIA standard, not many implementationshttp://www.snia.org/cdmi

• Nimbus.IO: https://nimbus.io

• MS-Azzure blob Storage:http://www.windowsazure.com/en-us/manage/services/storage/

• RackSpace Cloud Files:www.rackspace.com/cloud/files/

3rd EUDAT Technuical meeting in Bologna 7th February 2013

S3 and S3-like in commercial systems:

• S3 re-sellers:• Lots of services

• Including Dropbox

• Services similar to S3 concept:• Nimbus.IO:

https://nimbus.io

• MS-Azzure blob Storage:http://www.windowsazure.com/en-us/manage/services/storage/

• RackSpace Cloud Files:www.rackspace.com/cloud/files/

• S3 implementations ‚in the hardware’:• Xyratex

• Amplidata

3rd EUDAT Technuical meeting in Bologna 7th February 2013

o

Why build PRIVATE S3-like storage?• Features/ benefits:

• Reliable storage on top of commodity hardware

• User still able to control the data

• Easy scalability, possible to grow the system• Adding resources and redistributing data possible in non-disruptive way

• Open source software solutions and standards available:

• e.g. OpenStack Swift: Open Stack Native API and S3 API

• Other S3-enabled storage: e.g. RADOS

• CDMI: Cloud Data Management Interface

3rd EUDAT Technuical meeting in Bologna 7th February 2013

Why to federate iRODS with S3/OpenStack?

• Some communities have data stored in OpenStack

• VPH is building reliable storage cloud on top of OpenStack Swift within pMedicine project (together with PSNC)

• These data should be available to EUDAT

• Data Staging: Cloud -> EUDAT -> PRACE HPC and back

• Data Replication: Cloud -> EUDAT -> other back-end storage

• We could apply rule engine to data in the cloud, assign PIDs

3rd EUDAT Technuical meeting in Bologna 7th February 2013

• We were asked to consider cloud storage:

• From EUDAT 1st year review report:

EUDAT’s iRODS federation

VPH case analysis:

iRODS server

S3 driver

S3 APIOSS API

iRODS server

other storage driver

Storage system

S3/OSS

client

iRODS client

HPC system

iRODS server

storage driver

Data access

Data ingestion

Regi-stration

Data Staging

EUDAT’s PID Service

Replication

Dataingestion

Dataaccess

Dataaccess

PIDassigned

Our 7.2 project

• Purpose:

• To examine existing iRODS-S3 driver

• (possibly) to improve it / provide another one

• Steps/status:

• 1st stage:• Play with what is there – done for OpenStack/S3 + iRODS

• Examine functionality

• Evaluate scalability – found some issues already

• Follow-up• Try to improve the existing S3 driver

• Functionality

• Performance

• Implement native Open Stack driver?

• Get in touch with iRODS developers

3rd EUDAT Technuical meeting in Bologna 7th February 2013

iRODS-OpenStack tests

TEST SETUP:• iRODS server:

• Cloud as compoundresources

• Disk cache in front of it

• Open Stack Swift:

• 3 proxies, 1 with S3

• 5 storage nodes

• Extensive functionality and perf. tests

• Amazon S3:

• Only limited functionality tests

3rd EUDAT Technuical meeting in Bologna 7th February 2013

S3/OpenStack API

S3 API

iRODS server(s)

iRODS-OpenStack test

TEST RESULTS:

• S3 vs native OSS overhead• Upload: ~0%

• Download: ~8%

• iRODS overhead:

• Upload: ~19%

• Download:• From compound S3: ~0%

• Cached: SPEEDUP: 230%

(cache resources faster than S3)

iRODS-OpenStack test

Conclusions and future plans:

• Conclusions

• Performance-wise iRODS does not bring much overhead – files <2GB

• Problems arise for files >2GB – no support for multipart upload in iRODS-S3 driver – this prevents iRODS from storing files >2GB in clouds

• Some functional limits (e.g. imv problem)

• Using iRODS to federate S3 clouds in large scalewould require improving the existing or developing a new driver

• Future plans:

• Test the integration with VPH’s cloud using existing driver

• Ask SAF for supporting the driver development

• Get in touch with iRODS developers to assure the sustainability of our work

EUDAT’s iRODS federation

Object storage on top of iRODS?

S3 driver

S3 API S3/OSS

client

iRODS client

Data Access/

ingest

Dataingestion

Dataaccess

iRODS server

Other storage

iRODS server

other storage driver

Storage system Storage system

iRODS API S3 API

Problems:• Data organisation mapping: * filesystem vs objects * big files vs fragments

• Identity mapping? * S3 keys/accounts vs X.509?

• Out of scope of EUDAT? * a lot of work needed