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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Eco-Efficient Cloud Resource Monitoring and Analysis</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Axel Tenschert</string-name>
          <email>tenschert@hlrs.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Pavel Skvortsov</string-name>
          <email>skvortsov@hlrs.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Michael Gienger</string-name>
          <email>gienger@hlrs.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>HLRS - High Performance Computing Center University of Stuttgart Stuttgart</institution>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2014</year>
      </pub-date>
      <abstract>
        <p>-This paper presents an approach for monitoring cloud computing resources by using customized monitoring metrics. In addition, based on the monitoring results, this approach includes a data mining analysis for making assumptions regarding consumed power of infrastructure and virtual machines (VMs) aiming at a reduced carbon footprint. Index Terms-Cloud computing, Monitoring, Data Mining, Eco-efficiency, Carbon footprint</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>I. INTRODUCTION</title>
      <p>This work presents an enhanced monitoring approach
considering the infrastructure of providers’ sites and the virtual
machines (VMs) hosted on physical nodes. It considers the
GAMES [1] and the OPTIMIS [2] projects, that were both
developing methods for energy-aware resource usage. As the
monitoring infrastructure (figure 1) is based on standardized
software, customization is the goal for ensuring the relevant
values to reduce the power consumption and in addition, the
eco-efficiency of the infrastructure providers and the overall
carbon footprint.
server being connected to Zabbix client agents installed on
each physical node. Additionally, a data mining analysis is
performed on the monitored data set.</p>
      <p>The developed and implemented concept for monitoring
cloud resources makes use of the European funded BonFIRE
[4] project that was extended by the ECO2Clouds [5] project.
ECO2Clouds adapts and extends the already provided
monitoring capabilities by the providers EPCC, INRIA and
HLRS with the aim to reduce the power consumption and
improve the carbon footprint through monitoring and analyzing
required data. One major step of the overall approach is to
elaborate the power consumption of VMs.</p>
      <p>
        This paper is structured as follows: (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) Introduction, (
        <xref ref-type="bibr" rid="ref2">2</xref>
        )
Monitoring and Metrics, (
        <xref ref-type="bibr" rid="ref3">3</xref>
        ) Data Mining Analysis and (4)
Conclusions.
      </p>
    </sec>
    <sec id="sec-2">
      <title>II. MONITORING AND METRICS</title>
      <p>The ECO2Clouds monitoring system is a layered approach
distinguishing mainly between the physical infrastructure and
the virtualization layer. Additionally, applications can be
monitored as well but as this information is highly dependent
on the application, this paper won’t target the specific
application monitoring. For those three layers, a Zabbix client
agent is gathering monitoring information and sends it to the
Zabbix server in order to provide a monitoring information
repository to assist in optimization decision making. To enable
power measurements for all three layers, power distribution
units are attached to the physical servers. The monitored
parameters are derived as defined by customized monitoring
metrics based on standard programming languages like Python,
Ruby or even Bash.</p>
      <sec id="sec-2-1">
        <title>A. The infrastructure and virtualization layer</title>
        <p>The infrastructure layer is represented by the physical
infrastructure of a cloud provider, including physical nodes,
storages or network devices. Thus, the developed monitoring
approach needs to measure parameters of those physical
components in order to enable a data analysis based on the
current state of the infrastructure for making assumptions
regarding the overall system behavior. Besides the</p>
        <p>The presented monitoring approach demonstrates a
monitoring system making use of a Zabbix [3] monitoring
Copyright © papers' authors. Copying permitted only for private and academic purposes. This volume is published and
copyrighted by its editors.
infrastructure layer, especially the virtualization layer is a
crucial part as more or less the virtualization defines a
completely separated environment for applications. Thus, it is
essentially important to monitor those two layers in a fine
grained manner. Furthermore, for providing accurate
information for an optimized power consumption, both layers
have to be linked together by the creation of calculated metric
as presented in figure 2.</p>
        <p>It presents the structure of the layered approach by
presenting the virtual machines (VMs), the infrastructure and
the power distribution units (PDUs) for measuring the power
consumption of physical nodes and showing the connection of
those three via Zabbix to the three layers. To perform all
necessary calculations being defined in the set of monitoring
metrics the Zabbix server (infrastructure) and the aggregator
(Zabbix at VM level) need to be able to communicate to each
other.</p>
        <p>Coming back to the infrastructure layer, it refers to the
characteristics of the sites and the resources available in each of
them. Thus a set of metrics was defined for measuring relevant
infrastructure parameters and calculate them for enabling data
analysis.</p>
      </sec>
      <sec id="sec-2-2">
        <title>B. The virtualization layer</title>
        <p>The virtualization layer contains the underlying hypervisor
including the virtual machines (VMs) hosting the applications
(or part of applications) that are used to manage the cloud
infrastructure (e.g., the monitoring system) or that are offered
to the users (e.g., user specific business applications). In order
to create separated environments, the virtualization layer can be
freely configured: the amount of CPU, memory and disk space
can be aligned to the used application hosted inside.</p>
        <p>Metrics at the virtualization layer aim to characterize the
VMs on which the applications are running. They are analyzed
to evaluate if the current deployment can be further improved
and thus optimized. The analysis of the VM energy
consumption aims to understand how the energy consumed by
the host is distributed among the deployed VMs. Moreover,
new metrics were defined inspired by the data center metrics
(infrastructure) proposed in the last years, especially by The
Green Grid Consortium (GreenGrid). The idea is to redefine
the classical infrastructural metrics, like PUE and Data Centre
Energy Productivity (DCeP), at virtualization level to measure
the impact of the application tasks in terms of energy
consumption and carbon emissions.</p>
        <p>As already stated, the applications inside a VM can also be
monitored in particular. But due to the application character,
the metrics are highly specialized and cannot be regarded in a
generic fashion.</p>
      </sec>
      <sec id="sec-2-3">
        <title>C. The monitoring metrics</title>
        <p>This subsection will describe some of the most important
metrics to improve the energy consumption as well as the
carbon footprint for the infrastructure providers as well as for
the users.</p>
        <p>For improving the carbon footprint of an infrastructure
provider, metrics like “Carbon Usage Effectiveness of the
Provider”, “Green Efficiency Coefficient of the Electrical
Supplier” or the “Site Infrastructure Efficiency” are considered.
They are dealing with the amount of energy consumed and in
particular, on which basis the requested energy was generated.
As presented in the Data Mining section, there are big
differences in the amount of CO2 created to power the
machines at different days or even times. For infrastructure
providers, the mandatory metrics are global: monitoring a
single host is not sufficient. In order to understand the
infrastructure load, metrics like “Service Availability” as well
as “Storage and CPU as well as Memory Utilization” are also
of interest and have to be considered.</p>
        <p>The power consumption of VMs depends on the size of a
VM defined through the used memory, the data I/O identified
through the send and receive activities, the disk activity
identified through the read and write operations and the
consumed CPU seconds. Thus, the infrastructure and the
virtualization layer are involved to derive the information for
this important metric (figure 3).</p>
        <p>Finally, the power information of a VM can be correlated
with the “Green Efficiency Coefficient of the Electrical
Supplier” resulting in additional metrics. But the results are
impressive: the calculation of the virtual machine power
consumption is possible and even more, the produced carbon
can be observed as well. Especially for distributed computing
and data centers, there are differences for the location and
timeslot hosting the virtual instances.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>III. DATA MINING ANALYSIS</title>
      <p>The monitoring infrastructure described before is producing
large amounts of data in a short period of time. This data is
being collected into Accounting DB by the Accounting
Service, which runs on a separate host. During our
experiments, we have observed that the size of the collected
Copyright © papers' authors. Copying permitted only for private and academic purposes. This volume is published and
copyrighted by its editors.
metrics data varies between 10 and 20 Mb per day. As the
result, the fast-growing SQL database of the Accounting
Service host may shortly reach the storage capacity limits of
the Accounting node. This would trigger the automatic deletion
of the old data by Zabbix. In order to avoid the loss of
historical raw data and to allow for its statistical analysis, we
have developed the ECO2Clouds Data Mining service (DM
Service). Next, we present architecture, concepts and analysis
principles of the DM Service in more detail.</p>
      <sec id="sec-3-1">
        <title>A. Architecture</title>
        <p>DM Service consists of two major components (figure 4).
The first component is running on the Accounting Service to
perform transfer of non-reduced metrics data to a remote data
storage (DM Storage), and to generate a reduced data set.</p>
        <p>The second component is DM Storage, which gathers the
non-reduced metrics data and performs statistical analysis over
them, e.g., correlation analysis over a large enough portion of
data. The resulting stable parameters of this analysis are
inserted into the Accounting DB as a separate table.</p>
        <p>Results transfer
Transfer manager
Reduction service</p>
        <p>DM Storage</p>
        <p>Data analysis service
Accounting DB</p>
      </sec>
      <sec id="sec-3-2">
        <title>B. Concept</title>
        <p>
          The Data Mining workflow consists of the following steps.
(
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) Triggered daily, the Accounting Service inserts the new
non-reduced data into the database of DM Storage. (
          <xref ref-type="bibr" rid="ref2">2</xref>
          )
Triggered daily, the Accounting Service performs the
reduction of the metrics data; the results of data reduction are
inserted into a separate database on the Accounting VM. (
          <xref ref-type="bibr" rid="ref3">3</xref>
          )
The initial non-reduced data are deleted – thus, each time the
Accounting Service has to perform operations over a metrics
data set which was produced only during the last 24 hours
        </p>
        <p>The resulting loss of data at the Accounting DB does not
affect the Scheduler functionality, because it does not use the
historical data for physical hosts, while for experiments we
only reduce the data of finished (non-active) experiments only.</p>
        <p>On the DM Storage side, the statistical analysis of the data
is performed. The results are inserted into Accounting DB.</p>
      </sec>
      <sec id="sec-3-3">
        <title>C. Implementation</title>
        <p>
          On the Accounting VM, we install a bash script which
performs the following operations: (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) Creates a temporary
SQL-dump of the current non-reduced “e2c_collector”
database. (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) Imports the generated SQL-dump into DM
Storage by inserting the rows incrementally to the previously
stored there data. (
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) Removes the temporary SQL-dump from
the Accounting VM. (4) Calls the reduction service
implemented as a Java program, which performs the data
reduction and inserts its results into a separate database on the
same VM.
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      </sec>
      <sec id="sec-3-4">
        <title>D. Data Analysis</title>
        <p>On the DM Storage side, the metrics data analysis is being
performed. The aim of statistical data analysis is to find
correlation patterns, which may help to define the deployment
strategies depending, for instance, on the time of the day.</p>
        <p>One example a pattern of the power consumption and
emissions depending on the time of the day is shown in Fig. 5.
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        <p>The presented monitoring architecture uses customized
monitoring metrics and enables a data analysis providing result
data regarding a cloud system behavior. The focus of the
approach is the monitoring and analysis of data related to the
used energy mix and consumed power on infrastructure and
virtualization level.</p>
        <p>Thus, it becomes possible to align the VM scheduling to the
workload of the physical infrastructure by considering the
power consumption and the carbon footprint through knowing
about the energy mix. Herewith, costs for consumed power and
CO2 emissions are reduced for a cloud infrastructure.</p>
        <p>Future work will be using the presented monitoring
infrastructure and the implemented metrics as basis for running
experiments and supporting the deployment of use cases.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>ACKNOWLEDGMENT</title>
      <p>This work has been supported by the ECO2Clouds project
(http://eco2clouds.eu/) and has been partly funded by the
European Commission’s IST activity of the 7th Framework
Programme under contract number 318048. This paper
expresses the opinions of the authors and not necessarily those
of the European Commission. The European Commission is
not liable for any use that may be made of the information
contained in this paper.</p>
      <p>Copyright © papers' authors. Copying permitted only for private and academic purposes. This volume is published and
copyrighted by its editors.</p>
    </sec>
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