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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>IWSG</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>EGI Applications On Demand Service</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Gergely Sipos</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>EGI Foundation Amsterdam</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Netherlands gergely.sipos@egi.eu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Diego Scardaci</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>INFN/EGI Foundation Catania</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Italy diego.scardaci@egi.eu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Giuseppe La Rocca</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Peter Solagna</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>EGI Foundation Amsterdam</institution>
          ,
          <country country="NL">Netherlands</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2017</year>
      </pub-date>
      <volume>19</volume>
      <fpage>19</fpage>
      <lpage>21</lpage>
      <abstract>
        <p>-This paper describes the new EGI 'Applications on demand service', that the EGI collaboration specifically designed for individual researchers, small research teams and early phase research infrastructures that do not have dedicated computational and storage resources, online applications and science gateways to perform scientific data analysis. The described service is available at http://access.egi.eu and through a lightweight registration and user identity vetting process allows user-friendly access to a growing number of scientific applications and application hosting frameworks (science gateways, VREs) that are configured to use the dedicated pool of cloud computing and HTC clusters from EGI. The service operates as an open and extensible 'hub' for providers and einfrastructure user support teams who wish to federated and share applications and services with individual researchers, or small, fragmented communities, typically referred to as 'the long tail of science'.</p>
      </abstract>
      <kwd-group>
        <kwd>long-tail</kwd>
        <kwd>HTC/HPC</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>SaaS;
e-infrastructures;
cloud;</p>
    </sec>
    <sec id="sec-2">
      <title>I. INTRODUCTION</title>
      <p>EGI is an e-Infrastructure collaboration that provides
advanced computing and data services for research and
innovation. The collaboration operates a federated,
publiclyfunded e-infrastructure that currently comprises more than 300
resource centers from Europe and beyond. Over the last decade
this infrastructure was the enabler of digital research conducted
by over 40,000 researchers through the whole spectrum of
science from High-Energy Physics, to Earth Sciences, Life
Sciences, Chemistry, Astrophysics, and Humanities.</p>
      <p>
        EGI resource centers rely on the expertise of the ‘EGI
Foundation’, EGI’s coordinating institute located in
Amsterdam. EGI members – national compute/data centers (so
called NGIs) and Intergovernmental Research Organizations,
such as CERN – operate the compute, storage, application and
software services that comprise the ‘EGI infrastructure’. These
compute/storage providers allocate resources to scientific
communities via ‘Virtual Organisations’ (VOs), according to
institutional or regional/national priorities. A VO is the online
representation of a scientific user group whose members are
usually work in similar or related research areas, or are part of
the same scientific collaboration, for which reason they need
the same applications, software and underlying hardware
capabilities. Some of the biggest VOs of EGI represent
experiments of the Large Hadron Collider (ALICE, ATLAS,
CMS, LHCb) [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], the VIRGO experiment [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], the Cerenkov
Telescope Array Observatory [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] or life science researchers
from multiple countries and diverse background (biomed VO)
[
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>
        Since its start in 2010, EGI has well defined processes to
create and operate VOs for large, structured, international user
communities. These communities have well established and
long-term presence, moreover they are resourced well enough
to sustain skilled IT support teams who can instantiate and
operate VO services for the researchers. The most advanced
research infrastructures from the ESFRI Research
Infrastructure Roadmap [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] are the typical operators of the
largest VOs in EGI.
      </p>
      <p>At the same time individual researchers, small research
teams and members of early phase research infrastructures
often struggle to access applications, compute and data services
in EGI. The tools and resource allocation policies that were
designed for long-living, structured communities were
recognized as unsuitable for these type of users because they
typically involve:
•
•
•</p>
      <p>Obtaining and using an X.509 personal digital
certificate from Certification Authority (CA)
recognized by EGI.</p>
      <p>Joining an existing VO that matches the requester’s
research subject/goals, or setting up a new VO.</p>
      <p>Integrating relevant scientific applications with the VO
and fulfilling operational responsibilities, such as VO
membership management, resource
negotiations and community/application
service monitoring.
allocation
specific</p>
      <p>
        These individuals are often referred to as the ‘long tail of
science’ [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] and they share the common characteristic of (1)
missing dedicated arrangement to computational and storage
resources and online applications and services to manage and
analyze large amount of data, and (2) lacking the skills and
experience with deploying and scaling applications to
distributed computer architectures. Despite some NGIs operate
national services for the long tail of science, such national
‘catch-all’ VOs are not available or not well maintained any
more in several cases [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ].
      </p>
      <p>Recognizing the needs of this unique group, and trying to
compensate for the loss of NGI services in this domain we
designed and developed a new service within EGI: the
‘Applications on demand service’. The service was designed in
late 2014, demonstrated in November 2015, reached Alpha
release for early adopters in January 2017, and was opened for
the general public in April 2017 as a Beta1 service. The service
is available at http://access.egi.eu.</p>
      <p>This paper introduces this new service offering and details
the technologies and components that were developed and
integrated to realize the service. The rest of the paper is
organized as follows: Section II introduces the user and
provider requirements that drove the system development.
Section III describes the overall architecture and the main
design considerations. Section IV provides details about the
different system components that were developed/customized
from existing EGI tools to establish the service. Section V in a
table the already integrated applications and components of the
service. In Section VI we describe the steps that an applications
hosting framework provider has to follow to make his
framework accessible within the EGI Applications on Demand
service. In Section VII we present our plans for the extensions
and improvement of the service, while in Section VIII we draw
conclusions from the described work.</p>
    </sec>
    <sec id="sec-3">
      <title>II. REQUIREMENTS</title>
      <p>The design process for the new service started with a
requirement collection and analysis that helped us to
understand the needs/preferences of the long tail of science, as
well as the constraints from the EGI resource/service
providers’ side that we have to consider as we are aiming at a
sustainable service. These needs and constraints are
summaries in this section:
A. Users’ needs:
1. Zero-barrier access: any user who carries out
non-forprofit research should be able to get an account with a
‘start-up’ resource allocation on EGI to access scalable
application services together with the underlying
cloud/HTC/storage resources.
1 EGI Beta service: Service being developed while available for
testing publicly.
2. 100% coverage: anyone with Internet access can
become a user, no need to ask for personal travel to
obtain special credentials (e.g. X.509 certificate).
3. Extendible and open: The service must be extendible
with additional application services to support
specialized scientific disciplines and users. The
extension should be possible via open interfaces and
protocols.
4. User-centric: Support for users should be available in as
many EGI member countries as possible.</p>
      <p>B. Service providers’ constaints:
1. Realistic: Define an architecture that’s implementable
under the available effort levels. Reuse existing EGI
technological building blocks as much as possible.
2. Secure: Provide as high quality user identity vetting,
and tracking of user activities as possible (close to the
existing solutions that are based on personal X.509
certificates).
3. Scalable: Be able to scale to 100s of
compute/data/application providers. (The number and
size of providers limits the users too).
4. Recognized: Have sufficient policies and tools that
enforce the users to acknowledge the use of the service
in scientific publications resulted from this use.</p>
    </sec>
    <sec id="sec-4">
      <title>III. IMPLEMENTATION</title>
      <p>The architecture of the Applications on Demand service is
presented in Figure 1. In the heart of the service there is a 'User
Registration Portal' (URP). This is where new users enter to the
service. The list of applications and underpinning services can
be publicly browsed on the URP. Usage requires login. Login
is possible with Google, Facebook and EGI Single-Sign-On
accounts – All un-vetted accounts that are available for anyone
with Internet access. Within the URP the user can setup a
personal profile and can submit a resource access requests. The
request includes an estimate of the compute and storage
capacity that the user would like to use through the
application(s) he/she would like to use in the service. The
request can use the default capacity allocation (at the time of
writing this is 1000 CPUh and 10 TB storage) or can be a
customized request.</p>
      <p>The access request is forwarded to the distributed service
support team. A team member – from the applicant’s country
or from the EGI Foundation responds to the request and vets
the user identity, checks the capacity request. The vetting is
done by assessing the validity of the information provided by
the user in the profile, including links to departmental websites
and scientific publications and projects relating to the requested
e-infrastructure use. If needed, the support teams contacts the
applicant in email or by phone. Routing the access requests to
national EGI members not only allows us to conduct such
conversation in local languages, but also to connect long tail
users to national EGI support teams, reaching recognition and
trust in national e-infrastructure initiatives. If the capacity
request exceeds the default allocation then the estimate is
double-checked and if needed negotiated resource providers of
the service.</p>
      <p>After the applicant’s resource access request is approved,
the user profile is set to ‘active’ in the URP. This information is
propagated to the connected application hosting environments
(science gateways, Virtual Research Environments or similar).
These environments operate as applications hosting
frameworks, being equipped with a set of applications and user
interfaces, manuals/guides best suited for those applications.
For example, some gateways can be suited for workflow type
applications, others for parameter study jobs, yet others for
applications of a certain scientific discipline. The service is
open for any application hosting framework (See Section VI
for more details). Science gateway and Virtual Research
Environments supported by the European Commission FP7 and
H2020 work programmes are for example ideal candidates for
integration.</p>
      <p>
        Approved users can login to any of the connected
application hosting frameworks and use the embedded
applications. These applications are already configured to scale
to the distributed compute and storage systems that are
contributed to the service by EGI members. The resources are
made accessible for the applications in the form of
Infrastructure as a Service clouds joint into the ‘EGI Federated
Cloud’ [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ], or cluster resources federated with grid
middleware into the EGI ‘HTC Service’ [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ].
      </p>
      <p>The application use generates load on these resources and
this is reported by the resources into the EGI accounting
system. From this accounting system the user support teams
can obtain statistics about individual users, as well as about
application hosting frameworks, cloud/HTC/HPC sites. When
a user exceeds the amount of compute/storage/network
capacity that was allocated for him/her, the account can be
suspended in the URP, blocking the user from further
consumption through this service. The continued use requires a
new justification from the user and a corresponding evaluation
by the support team.</p>
    </sec>
    <sec id="sec-5">
      <title>IV. ENABLING TECHNOLOGIES</title>
      <p>
        The service was created by customizing various existing
EGI components, and by developing a few new ones in order to
glue together the required elements into a single service. The
following customizations and developments were made:
• The User Registration Portal (URP) was developed by
CYFRONET as an extension of the e-GRANT EGI
resource allocation tool [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. The URP includes forms
that guide users through the profile setup, resource
request and application selection workflow. The tool
was extended with web forms and an email notification
subsystem to help the distributed user support team
during the user identity vetting and user approval
process. The URP provides an identity federation for the
whole service, i.e. a user can authenticate to this portal
and after his/her account is validated he/she will be able
to login to any of the connected application hosting
frameworks and respective hosted applications.
•
•
      </p>
      <p>
        A resource pool was formed from EGI cloud and HTC
sites. The participating sites feel institutionally or
nationally responsible for supporting the long tail of
science, and therefore contribute with capacity into this
pool. The sites are joined together into an EGI Virtual
Organization called ‘vo.access.egi.eu’ [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]. The sites in
this pool accept special X.509 proxy certificates that are
unique for the Applications on demand service and
which identify user workloads from the application
hosting frameworks (See details under next point). At
the time of writing the resource pool includes cloud
resources from Italy (INFN-Catania and INFN-Bari)
and Spain (BIFI, CESGA) and HTC clusters from
Belgium (VUB), Italy (INFN-Catania and INFN-Bari),
Poland (CYFRONET) and Spain (CESGA).
      </p>
      <p>
        Access to EGI resources requires short-living X.509
proxy certificates from the client side. The traditional
method is to generate such proxies either from a
longterm personal certificate, or from a robot certificate [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]
that is used by an application hosting framework.
Unfortunately neither of these approaches were
sufficient for the Applications on Demand service,
because (1) personal certificates are found difficult to
handle or impossible to obtain by certain long tail users,
and (2) robot-proxies do not include any information
about the individual end-users, hiding all users
workload under a single identity, making impossible for
the identification of excessive or harmful use by certain
individuals. To overcome these limitations a new,
socalled ‘Per-User Sub-Proxy’ (PUSP) mechanism was
developed. PSUPs are short-term proxies that are
generated from robot certificates in a special way: The
‘distinguished name’ (DN) field of the proxy includes a
unique string that is specific to the requester user. The
DN is the same for a specific user for multiple user
sessions, even if those sessions are initiated by different
application hosting frameworks. The compute and
storage resources report the proxy DN into the EGI
accounting system, and based on the user-specific DNs
we are able to trace back every e-infrastructure
operation to the initiating user. The user-specific strings
are generated during the identity vetting and approval
process, and they are propagated to every participating
application hosting framework. This tracing process is
graphically presented in Figure 2.
• The connected application hosting frameworks must
generate PSUPs from robot certificates. This is possible
in two ways: (1) from a robot certificate that is deployed
either locally on a USB smartcard on the server that
hosts the framework. (2) Because robot certificates are
not available from EGI-recognised CAs in every
country, we setup an ‘eToken server’ at INFN-Catania
that can serve any participating application hosting
frameworks with PSUPs. The application hosting
frameworks can send a PSUP generation request to the
server via its network API, including the userID as a
parameter. The eToken server responds with the
shortterm proxy certificate that can be used by the
framework to interact with the VO resources (See step 5
and 6 in Figure 2.).
      </p>
      <p>
        Application hosting frameworks that can provide
userfriendly interfaces to conduct scientific applications on
VO platform resources in cloud or HTC/HPC clusters.
The gateways use the identity federation of the URP to
allow access to approved users, and user the PUSP
mechanism to interact with cloud and HTC resources.
The service currently includes three applications hosting
frameworks: the WS-PGRADE [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ], the EC3/IM [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]
and the CSG [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]. The service is open for any additional
framework that wish to make applications and
application development/hosting services available at
the European/worldwide scale. Technical instructions to
integrate a new applications hosting framework to the
service are provided in Section VI.
o
o
o
o
o
      </p>
    </sec>
    <sec id="sec-6">
      <title>V. ELEMENTS OF THE SERVICE</title>
      <p>The following Table 1 provides a summary of the
components that are currently operated within the EGI
Applications on Demand service.</p>
      <p>• 17 applications from different scientific areas and tools
have been already integrated into the existing
applications hosting frameworks and are offered ‘as
services’ to users:
• Two policies were developed: A security policy for
resource centers offering cloud/HTC/HPC/storage and
an Acceptable Use Policy (AUP) for users.</p>
    </sec>
    <sec id="sec-7">
      <title>Molecular Docking, Workflow and parameter study tool (WS-PGRADE portal).</title>
    </sec>
    <sec id="sec-8">
      <title>Galaxy, Docker, Octave, Apache Tomcat, GnuPlot, NAMD, Hadoop, Marathon, Chronos, Jupyter Notebook, Cloud orchestrator (in the EC3/IM portal).</title>
    </sec>
    <sec id="sec-9">
      <title>Chipster, ClustalW2, Semantic Search, the Statistical R for Computing (in the Catania Science Gateway).</title>
    </sec>
    <sec id="sec-10">
      <title>Additional applications will be integrated into the frameworks following cost-value assessment (more impactful, more broadly relevant applications have priority).</title>
    </sec>
    <sec id="sec-11">
      <title>The first policy is compulsory to accept and</title>
      <p>implement by participating Resource Centers. The
policy defines that offering resources in this
service shall not negatively affect the security or
change the security risk of any other VO. In
particular, security incidents originating in the
Applications on Demand service should not
impact the IT Infrastructure in ways that are
incompatible with the operational model of other
VOs. This document also provides guidelines on
the implementation of security procedures and
controls to facilitate offering of the Service by
Resource Centers and Science Gateways. The
Guidelines contain normative information on how
to implement the Policy.</p>
    </sec>
    <sec id="sec-12">
      <title>The user AUP defines the conditions of use, and</title>
      <p>responsibilities of the users – such as using the
services only for activities that relate to the work
that was described in the access request form; or
what text to use in scientific publications to
acknowledge the use of the infrastructure.</p>
      <p>
        This section provides a short overview of the integration
steps that gateway/VRE providers must complete to contribute
to the service. Interested providers should consult with the
online manual for details [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. Compute and storage providers
(cloud, HTC) can join the service by federating into the
‘vo.access.egi.eu’ Virtual Organisation [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ], following the
regular EGI guides for resource providers.
      </p>
      <p>There are two fundamental prerequisites of integrating an
application hosting framework: (1) the framework must be a
mature technology2 with demonstrated use within publicly
funded science and (2) the framework must be already able to
use cloud, HTC or data services from EGI, or be ready to do
so (to enable the scale-out of the hosted applications).</p>
      <p>
        As reported in the previous Sections, the URP provides the
identity federation that enables users to authenticate in any of
the connected application hosting frameworks with either
social credentials or EGI SSO accounts. In the current
implementation, this identity federation is implemented with
Unity [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ], an authentication &amp; authorization management
solution that uses OpenID Connect as standard interface. The
2 For example at ‘Technology Readiness Level 8 or 9 [
        <xref ref-type="bibr" rid="ref24">24</xref>
        ]
first requirement to integrate a new applications hosting
framework into the service is to register the framework in
Unity to get a clientID and secretKey. These credentials will
be used by Unity to identify the new provider and implement a
secure connection with it.
      </p>
      <p>
        For applications hosting frameworks based on Liferay
technology INFN-Catania has developed an OpenID Connect
module [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ] that enables Liferay-based gateways to
authenticate with OpenID Connect providers. This module is
adopted by the WS-PGRADE and CSG frameworks within
this service.
      </p>
      <p>A second step of integration is using the userID provided
by Unity to generate Per-User Sub-Proxies (PUSP) to secure
user interaction with the EGI resources. For this, the provider
can rely on the eToken server that was already presented in the
previous Section.</p>
      <p>
        Lastly, the technical integration is complete when the
service support team together with the framework provider 1.)
registers the framework in the EGI service registry (GOCDB)
to activate the availability and reliability monitoring for the
framework with the EGI ARGO service [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], 2.) setup a
framework-specific support unit in EGI Helpdesk [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] (this is
for example tickets will be opened when the framework is
noticed inaccessible by the monitor system and 3.) sign an
Operation Level Agreement (OLA) defining for example
availability and reliability targets, helpdesk ticket response
times.
      </p>
    </sec>
    <sec id="sec-13">
      <title>VII. FUTURE WORK</title>
      <p>
        The ‘EGI Applications on Demand service’ was opened
for public use in April 2017. In the next few months we are
working on promoting the system to potential users, mainly
through the user support teams of EGI member states.
Promotion will be focused on countries where national support
is lacking or insufficient for the long tail of science.
In parallel with broadening the uptake of the new service we
are also planning to improve/expand the technical setup. This
work will cover the following areas:
1. Replacing PUSPs with short-term proxies generated by
the RC Auth service [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ]. RC Auth was designed by the
AARC H2020 project [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ] to have an open, European
proxy factory service that can be used by any
einfrastructure and Research Infrastructure that needs
X.509 proxies for service access. The use of RC Auth in
the EGI Applications on Demand service would improve
the compatibility of our architecture with other European
initiatives, simplifying the integration of additional
applications and hosting environments. Besides, the
change would improve the sustainability of our setup, by
eliminating components that EGI currently has to sustain
alone.
2. In the current architecture every application framework
and application should implement its own tools to
manage the users’ scientific data (for example importing
data into the infrastructure from external storage systems,
exporting results into external repositories). We are
planning to integrate a data management service (or
layer) into the EGI Applications on Demand service that
could be used by all applications hosting frameworks for
data management. If properly designed, the service could
also help users curate and archive application outputs,
tackling the problem of ‘dark data in the long tail’ [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ].
The details of this data management layer are yet to be
defined.
3. The current EGI flagship project, EGI-Engage [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ], is
close to establishing an ‘EGI Marketplace’. This
marketplace would offer a one-stop-shop for individual
researchers, research communities and industry to
browse and request services from EGI. The EGI
Applications on Demand service and/or its individual
services will have to be connected/integrated into this
marketplace to make them visible and accessible for
potential users and customers. This will require some
sort of merge of the URP into the EGI Marketplace.
      </p>
    </sec>
    <sec id="sec-14">
      <title>VIII. CONCLUSIONS</title>
      <p>In this paper we presented a new EGI Applications on
Demand service. The service is specifically designed to cater
for the needs of individual researchers, small research
collaborations and early-phase Research Infrastructures. The
service provides easy to use environments for these user
communities to request and access scalable scientific
applications and application porting environments. The service
includes also distributed computing and storage resources, and
eliminates the need for users to form community-specific
agreements with EGI providers, and to sustain skilled IT
teams to operate VO services.</p>
      <p>The new service does not replace the ‘traditional’,
community/project specific and national VOs of EGI.
Structured scientific collaborations and mature Research
Infrastructures continue to require dedicated VOs in EGI
because only those can host fully customized,
communityspecific services and only they can offer dedicated compute
and storage capacity at extreme scales. National ‘long tail
VOs’ are also here to remain in those NGIs that have effort to
support local users with national services. The EGI
Foundation continues to negotiate and secure services for
community-specific VO through Service Level and
Operational Level Agreements (SLAs, OLAs).</p>
    </sec>
    <sec id="sec-15">
      <title>ACKNOWLEDGMENT</title>
      <p>The work presented in this paper has been supported by the
EGI-Engage H2020 project (Grant number 654142). The
authors would like to thank the contribution to the
implementation of the described service to the following
institutes: BIFI, CESGA, CNRS, CYFRONET, INFN-Catania,
INFN-Bari, NIKHEF, SZTAKI, ULB-VUB, UPV.</p>
    </sec>
  </body>
  <back>
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