Deploy Ceph and start using it: end to end tutorial – simple librados client (part 3/3)

(Part 1/3 – Installation – Part 2/3 – troubleshooting)

This part of the tutorial describes how to setup a simple Ceph client using librados (for C++).

The only information that the client requires for the cephx authentication is

  • Endpoint of the monitor node
  • Keyring containing the pre-shared secret (we will use the admin keyring)

Install librados APIs

On Ubuntu, the library is available on the repositories

$ sudo apt-get install librados-dev

Create a client configuration file

This is the file from which librados will read the client configuration.

The content of the file is structured according to this template:

[global]
mon host= <IP address of one of the monitors>
keyring = <path/to/client.admin.keyring>

for example:

[global]
mon host = 192.168.252.10:6789
keyring = ./ceph.client.admin.keyring

The public endpoint of the monitor node can be retrieved with

$ ceph mon stat

The keyring file can be copied from the admin node. No change is needed to this file. The same information that is contained in the file can be retrieved with this command that will also list the client capabilities:

$ ceph auth get client.admin

Connect to the cluster

The following simple client will perform the following operations:

  • Read the configuration file (ceph.conf) from the local directory
  • Get an handle to the cluster and IO context on the “data” pool
  • Create a new object
  • Set an xattr
  • Read the object and xattr back
  • Print the list of pools
  • Print the list of objects in the “data” pool
  • Cleanup
  1. #include <rados/librados.hpp>
  2. #include <string>
  3. #include <list>
  4. int main(int argc, const char **argv)
  5. {
  6.   int ret = 0;
  7.   /*
  8.    * Errors are not checked to avoid pollution.
  9.    * After each Ceph operation:
  10.    * if (ret < 0) error_condition
  11.    * else success
  12.    */
  13.   // Get cluster handle and connect to cluster
  14.   std::string cluster_name(“ceph”);
  15.   std::string user_name(“client.admin”);
  16.   librados::Rados cluster;
  17.   cluster.init2(user_name.c_str(), cluster_name.c_str()0);
  18.   cluster.conf_read_file(“ceph.conf”);
  19.   cluster.connect();
  20.   // IO context
  21.   librados::IoCtx io_ctx;
  22.   std::string pool_name(“data”);
  23.   cluster.ioctx_create(pool_name.c_str(), io_ctx);
  24.   // Write an object synchronously
  25.   librados::bufferlist bl;
  26.   std::string objectId(“hw”);
  27.   std::string objectContent(“Hello World!”);
  28.   bl.append(objectContent);
  29.   io_ctx.write(objectId, bl, objectContent.size()0);
  30.   // Add an xattr to the object.
  31.   librados::bufferlist lang_bl;
  32.   lang_bl.append(“en_US”);
  33.   io_ctx.setxattr(objectId, “lang”, lang_bl);
  34.   // Read the object back asynchronously
  35.   librados::bufferlist read_buf;
  36.   int read_len = 4194304;
  37.   //Create I/O Completion.
  38.   librados::AioCompletion *read_completion =
  39.                                              librados::Rados::aio_create_completion();
  40.   //Send read request.
  41.   io_ctx.aio_read(objectId, read_completion, &read_buf, read_len, 0);
  42.   // Wait for the request to complete, and print content
  43.   read_completion>wait_for_complete();
  44.   read_completion>get_return_value();
  45.   std::cout << “Object name: “ << objectId << \n
  46.             << “Content: “ << read_buf.c_str() << std::endl;
  47.   // Read the xattr.
  48.   librados::bufferlist lang_res;
  49.   io_ctx.getxattr(objectId, “lang”, lang_res);
  50.   std::cout << “Object xattr: “ << lang_res.c_str() << std::endl;
  51.   // Print the list of pools
  52.   std::list<std::string> pools;
  53.   cluster.pool_list(pools);
  54.   std::cout << “List of pools from this cluster handle” << std::endl;
  55.   for (auto pool_id : pools) {
  56.     std::cout << \t << pool_id << std::endl;
  57.   }
  58.   // Print the list of objects
  59.   librados::ObjectIterator oit = io_ctx.objects_begin();
  60.   librados::ObjectIterator oet = io_ctx.objects_end();
  61.   std::cout << “List of objects from this pool” << std::endl;
  62.   for (; oit != oet; oit++) {
  63.     std::cout << \t << oit>first << std::endl;
  64.   }
  65.   // Remove the xattr
  66.   io_ctx.rmxattr(objectId, “lang”);
  67.   // Remove the object.
  68.   io_ctx.remove(objectId);
  69.   // Cleanup
  70.   io_ctx.close();
  71.   cluster.shutdown();
  72.   return 0;
  73. }

Find the pastebin here.

This example can be compiled and executed with

$ g++ client.cpp -lrados -o cephclient
$ ./cephclient

Operate with cluster data from the command line

To quickly verify if an object was written or to remove it, use the following commands (e.g., from the monitor node).

  • List objects in pool data

    $ rados -p data ls
  • Check the location of an object in pool data

    $ ceph osd map data <object name>
  • Remove object from pool data

    $ rados rm <object name> --pool=data

Deploy Ceph and start using it: end to end tutorial – Troubleshooting (part 2/3)

(Part 1/3 – Installation – Part 3/3 – librados client)

It is quite common that after the initial installation, the Ceph cluster reports health warnings. Before using the cluster for storage (e.g., allow clients to access it), a HEALTH_OK state should be reached:

cluster-admin@ceph-mon0:~/ceph-cluster$ ceph health
HEALTH_OK

This part of the tutorial provides some troubleshooting hints that I collected during the setup of my deployments. Other helpful resources are the Ceph IRC channel and mailing lists.

Useful diagnostic commands

A collection of diagnostic commands to check the status of the cluster is listed here. Running these commands is how we can understand that the Ceph cluster is not properly configured.

  1. Ceph status
    $ ceph status

    In this example, the disk for one OSD had been physically removed, so 2 out of 3 OSDs were in and up.

    cluster-admin@ceph-mon0:~/ceph-cluster$ ceph status
        cluster 28f9315e-6c5b-4cdc-9b2e-362e9ecf3509
         health HEALTH_OK
         monmap e1: 1 mons at {ceph-mon0=192.168.0.1:6789/0}, election epoch 1, quorum 0 ceph-mon0
         osdmap e122: 3 osds: 2 up, 2 in
          pgmap v4699: 192 pgs, 3 pools, 0 bytes data, 0 objects
                87692 kB used, 1862 GB / 1862 GB avail
                     192 active+clean
  2. Ceph health
    $ ceph health
    $ ceph health detail
  3. Pools and OSDs configuration and status
    $ ceph osd dump
    $ ceph osd dump --format=json-pretty

    the second version provides much more information, listing all the pools and OSDs and their configuration parameters

  4. Tree of OSDs reflecting the CRUSH map
    $ ceph osd tree

    This is very useful to understand how the cluster is physically organized (e.g., which OSDs are running on which host).

  5. Listing the pools in the cluster
    $ ceph osd lspools

    This is particularly useful to check clients operations (e.g., if new pools were created).

  6. Check the CRUSH rules
    $ ceph osd crush dump --format=json-pretty
  7. List the disks of one node from the admin node
    $ ceph-deploy disk list osd0
  8. Check the logs.
    Log files in /var/log/ceph/ will provide a lot of information for troubleshooting. Each node of the cluster will contain logs about the Ceph components that it runs, so you may need to SSH on different hosts to have a complete diagnosis.

Check your firewall and network configuration

Every node of the Ceph cluster must be able to successfully run

$ ceph status

If this operation times out without giving any results, it is likely that the firewall (or network configuration) is not allowing the nodes to communicate.

Another symptom of this problem is that OSDs cannot be activated, i.e., the ceph-deploy osd activate <args> command will timeout.

Ceph monitor default port is 6789Ceph OSDs and MDS try to get the first available ports starting at 6800.

A typical Ceph cluster might need the following ports:

Mon:  6789
Mds:  6800
Osd1: 6801
Osd2: 6802
Osd3: 6803

Depending on your security requirements, you may want to simply allow any traffic to and from the Ceph cluster nodes.

References: http://comments.gmane.org/gmane.comp.file-systems.ceph.devel/2231

Try restarting first

Without going for fine troubleshootings and log analysis, sometimes (especially after the first installation), I’ve noticed that a simple restart of the Ceph components has helped the transition from a HEALTH_WARN to a HEALTH_OK state.

If some of the OSDs are not in or not up, like in the case below

    cluster 07d28faa-48ae-4356-a8e3-19d5b81e159e
     health HEALTH_WARN 192 pgs incomplete; 192 pgs stuck inactive; 192 pgs stuck unclean; 1/2 in osds are down; clock skew detected on mon.1, mon.2
     monmap e3: 3 mons at {0=192.168.252.10:6789/0,1=192.168.252.11:6789/0,2=192.168.252.12:6789/0}, election epoch 36, quorum 0,1,2 0,1,2
     osdmap e27: 6 osds: 1 up, 2 in
      pgmap v57: 192 pgs, 3 pools, 0 bytes data, 0 objects
            84456 kB used, 7865 MB / 7948 MB avail
                 192 incomplete

try to start the OSD daemons with

# on osd0
$ sudo /etc/init.d/ceph -a start osd0

If the OSDs are in, but PGs are in weird states, like in the example below

cluster 07d28faa-48ae-4356-a8e3-19d5b81e159e
     health HEALTH_WARN 192 pgs degraded; 192 pgs stuck unclean; clock skew detected on mon.1, mon.2
     monmap e3: 3 mons at {0=192.168.252.10:6789/0,1=192.168.252.11:6789/0,2=192.168.252.12:6789/0}, election epoch 36, quorum 0,1,2 0,1,2
     osdmap e34: 6 osds: 6 up, 6 in
      pgmap v71: 192 pgs, 3 pools, 0 bytes data, 0 objects
            235 MB used, 23608 MB / 23844 MB avail
                 128 active+degraded
                  64 active+replay+degraded

try to restart the monitor(s) with

# on mon0
$ sudo /etc/init.d/ceph -a restart mon0

Unfortunately, a simple restart will be the solution in just a few rare cases. More troubleshooting will be required in the majority of the situations.

Unable to find keyring

During the deployment of the monitor nodes (the ceph-deploy <mon> [<mon>] create-initial step), Ceph may complain about missing keyrings:

[ceph_deploy.gatherkeys][WARNIN] Unable to find
/etc/ceph/ceph.client.admin.keyring on ['ceph-server']

If this warning is reported (even if the message is not an error), the Ceph cluster will probably not reach an healthy state.

The solution to this problem is to use exactly the same names for the hostnames (i.e., the output of hostname -s) and the Ceph node names.

This means that the files

  • /etc/hosts
  • /etc/hostname
  • .ssh/config (only for the admin node)

and the result of the command hostname -s, all should have the same names for a certain node.

See also:

 Check that replication requirements can be met

I’ve found that most of my problems with Ceph health were related to wrong (i.e., unfeasible) replication policies.

This is particularly likely to happen in test deployment where one doesn’t care about setting up many OSDs or separating them across different hosts.

Some common pitfalls here may be:

  1. The number of required replicas is higher than the number of OSDs (!!)
  2. CRUSH is instructed to separate replicas across hosts but multiple OSDs are on the same host and there are not enough OSD hosts to satisfy this condition

The visible effect when running diagnostic commands is that PGs will be in wrong statuses.

CASE 1the replication level is such that it cannot be accomplished with the current cluster (e.g., a replica size of 3 with 2 OSDs).

Check the replicated size of pools with

$ ceph osd dump

Adjust the replicated size and min_size, if required, by running

$ ceph osd pool set <pool_name> size <value>
$ ceph osd pool set <pool_name> min_size <value>

CASE 2: the replication policy would require replicas to sit on separate hosts, but OSDs are running within the same hosts

Check what crush_ruleset applies to a certain pool with

$ ceph osd dump --format=json-pretty

In the example below, the pool with id 0 (“data”) is using the crush_ruleset with id 0

"pools": [
        { "pool": 0,
          "pool_name": "data",
          [...]
          "crush_ruleset": 0,  <----
          "object_hash": 2,
          [...]

then check with

$ ceph osd crush dump --format=json-pretty

what crush_ruleset 0 is about.

In the example below, we can observe that this rules says to replicate data by choosing the first available leaf in the CRUSH map, which is of type host.

"rules": [
        { "rule_id": 0,
          "rule_name": "replicated_ruleset",
          "ruleset": 0,
          "type": 1,
          "min_size": 1,
          "max_size": 10,
          "steps": [
                { "op": "take",
                  "item": -1,
                  "item_name": "default"},
                { "op": "chooseleaf_firstn",     <-----------
                  "num": 0,
                  "type": "host"},               <-----------
                { "op": "emit"}]}],

If not enough hosts are available, then the application of this rule will fail.

To allow replicas to be created on different OSDs but possibly on the same host, we need to create a new ruleset:

$ ceph osd crush rule create-simple replicate_within_hosts default osd

After the rule has been created, it should be listed in the output of

$ ceph osd crush dump

from where we can not its id.

The next step is to apply this rule to the pools as required:

$ ceph osd pool set data crush_ruleset <rulesetId>
$ ceph osd pool set metadata crush_ruleset <rulesetId>
$ ceph osd pool set rbd crush_ruleset <rulesetId>

Deploy Ceph and start using it: end to end tutorial – Installation (part 1/3)

Ceph is one of the most interesting distributed storage systems available, with a very active development and a complete set of features that make it a valuable candidate for cloud storage services. This tutorial goes through the required steps (and some related troubleshooting), required to setup a Ceph cluster and access it with a simple client using librados. Please refer to the Ceph documentation for detailed insights on Ceph components.

(Part 2/3 – Troubleshooting – Part 3/3 – librados client)

Assumptions

  • Ceph version: 0.79
  • Installation with ceph-deploy
  • Operating system for the Ceph nodes: Ubuntu 14.04

Cluster architecture

In a minimum Ceph deployment, a Ceph cluster includes one Ceph monitor (MON) and a number of Object Storage Devices (OSD).

Administrative and control operations are issued from an admin node, which must not necessarily be separated from the Ceph cluster (e.g., the monitor node can also act as the admin node). Metadata server nodes (MDS) are required only for Ceph Filesystem (Ceph Block Devices and Ceph Object Storage do not use MDS).

Preparing the storage

WARNING: preparing the storage for Ceph means to delete a disk’s partition table and lose all its data. Proceed only if you know exactly what you are doing!

Ceph will need some physical storage to be used as Object Storage Devices (OSD) and Journal. As the project documentation recommends, for better performance, the Journal should be on a separate drive than the OSD. Ceph supports ext4, btrfs and xfs. I tried setting up clusters with both btrfs and xfs, however I could achieve stable results only with xfs, so I will refer to this latter.

  1. Prepare a GPT partition table (I have observed stability issues when using a dos partition)
    $ sudo parted /dev/sd<x>
    (parted) mklabel gpt
    (parted) mkpart primary xfs 0 ­100%
    (parted) quit

    if parted complains about alignment issues (“Warning: The resulting partition is not properly aligned for best performance”), check this two links to find a solution: 1 and 2.

  2. Format the disk with xfs (you might need to install xfs tools with sudo apt-get install xfsprogs)
    $ sudo mkfs.xfs /dev/sd<x>1
  3. Create a Journal partition (raw/unformatted)
    $ sudo parted /dev/sd<y>
    (parted) mklabel gpt
    (parted) mkpart primary 0 100%

 Install Ceph deploy

The ceph-deploy tool must only be installed on the admin node. Access to the other nodes for configuration purposes will be handled by ceph-deploy over SSH (with keys).

  1. Add Ceph repository to your apt configuration, replace {ceph-stable-release} with the Ceph release name that you want to install (e.g., emperor, firefly, …)
    $ echo deb http://ceph.com/debian-{ceph-stable-release}/ $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph.list
  2. Install the trusted key with
    $ wget -q -O- 'https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.asc' | sudo apt-key add -
  3. If there is no repository for your Ubuntu version, you can try to select the newest one available by manually editing the file /etc/apt/sources.list.d/ceph.list and changing the Ubuntu codename (e.g., trusty -> raring)
    $ deb http://ceph.com/debian-emperor raring main
  4. Install ceph-deploy
    $ sudo apt-get update
    $ sudo apt-get install ceph-deploy

Setup the admin node

Each Ceph node will be setup with an user having passwordless sudo permissions and each node will store the public key of the admin node to allow for passwordless SSH access. With this configuration, ceph-deploy will be able to install and configure every node of the cluster.

NOTE: the hostnames (i.e., the output of hostname -s) must match the Ceph node names!

  1. [optional] Create a dedicated user for cluster administration (this is particularly useful if the admin node is part of the Ceph cluster)
    $ sudo useradd -d /home/cluster-admin -m cluster-admin -s /bin/bash

    then set a password and switch to the new user

    $ sudo passwd cluster-admin
    $ su cluster-admin
  2. Install SSH server on all the cluster nodes (even if a cluster node is also an admin node)
    $ sudo apt-get install openssh-server
  3. Add a ceph user on each Ceph cluster node (even if a cluster node is also an admin node) and give it passwordless sudo permissions
    $ sudo useradd -d /home/ceph -m ceph -s /bin/bash
    $ sudo passwd ceph
    <Enter password>
    $ echo "ceph ALL = (root) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ceph
    $ sudo chmod 0440 /etc/sudoers.d/ceph
  4. Edit the /etc/hosts file to add mappings to the cluster nodes. Example:
    $ cat /etc/hosts
    127.0.0.1       localhost
    192.168.58.2    mon0
    192.168.58.3    osd0
    192.168.58.4    osd1

    to enable dns resolution with the hosts file, install dnsmasq

    $ sudo apt-get install dnsmasq
  5. Generate a public key for the admin user and install it on every ceph nodes
    $ ssh-keygen
    $ ssh-copy-id ceph@mon0
    $ ssh-copy-id ceph@osd0
    $ ssh-copy-id ceph@osd1
  6. Setup an SSH access configuration by editing the .ssh/config file. Example:
    Host osd0
       Hostname osd0
       User ceph
    Host osd1
       Hostname osd1
       User ceph
    Host mon0
       Hostname mon0
       User ceph
  7. Before proceeding, check that ping and host commands work for each node
    $ ping mon0
    $ ping osd0
    ...
    $ host osd0
    $ host osd1

Setup the cluster

Administration of the cluster is done entirely from the admin node.

  1. Move to a dedicated directory to collect the files that ceph-deploy will generate. This will be the working directory for any further use of ceph-deploy
    $ mkdir ceph-cluster
    $ cd ceph-cluster
  2. Deploy the monitor node(s) – replace mon0 with the list of hostnames of the initial monitor nodes
    $ ceph-deploy new mon0
    [ceph_deploy.cli][INFO  ] Invoked (1.4.0): /usr/bin/ceph-deploy new mon0
    [ceph_deploy.new][DEBUG ] Creating new cluster named ceph
    [ceph_deploy.new][DEBUG ] Resolving host mon0
    [ceph_deploy.new][DEBUG ] Monitor mon0 at 192.168.58.2
    [ceph_deploy.new][INFO  ] making sure passwordless SSH succeeds
    [ceph_deploy.new][DEBUG ] Monitor initial members are ['mon0']
    [ceph_deploy.new][DEBUG ] Monitor addrs are ['192.168.58.2']
    [ceph_deploy.new][DEBUG ] Creating a random mon key...
    [ceph_deploy.new][DEBUG ] Writing initial config to ceph.conf...
    [ceph_deploy.new][DEBUG ] Writing monitor keyring to ceph.mon.keyring...
  3. Add a public network entry in the ceph.conf file if you have separate public and cluster networks (check the network configuration reference)
    public network = {ip-address}/{netmask}
  4. Install ceph in all the nodes of the cluster. Use the --no-adjust-repos option if you are using different apt configurations for ceph. NOTE: you may need to confirm the authenticity of the hosts if your accessing them on SSH for the first time!
    Example (replace mon0 osd0 osd1 with your node names):

    $ ceph-deploy install --no-adjust-repos mon0 osd0 osd1
  5. Create monitor and gather keys
    $ ceph-deploy mon create-initial
  6. The content of the working directory after this step should look like
    cadm@mon0:~/my-cluster$ ls
    ceph.bootstrap-mds.keyring  ceph.bootstrap-osd.keyring  ceph.client.admin.keyring  ceph.conf  ceph.log  ceph.mon.keyring  release.asc

Prepare OSDs and OSD Daemons

When deploying OSDs, consider that a single node can run multiple OSD Daemons and that the journal partition should be on a separate drive than the OSD for better performance.

  1. List disks on a node (replace osd0 with the name of your storage node(s))
    $ ceph-deploy disk list osd0

    This command is also useful for diagnostics: when an OSD is correctly mounted on Ceph, you should see entries similar to this one in the output:

    [ceph-osd1][DEBUG ] /dev/sdb :
    [ceph-osd1][DEBUG ] /dev/sdb1 other, xfs, mounted on /var/lib/ceph/osd/ceph-0
  2. If you haven’t already prepared your storage, or if you want to reformat a partition, use the zap command (WARNING: this will erase the partition)
    $ ceph-deploy disk zap --fs-type xfs osd0:/dev/sd<x>1
  3. Prepare and activate the disks (ceph-deploy also has a create command that should combine this two operations together, but for some reason it was not working for me). In this example, we are using /dev/sd<x>1 as OSD and /dev/sd<y>2 as journal on two different nodes, osd0 and osd1
    $ ceph-deploy osd prepare osd0:/dev/sd<x>1:/dev/sd<y>2 osd1:/dev/sd<x>1:/dev/sd<y>2
    $ ceph-deploy osd activate osd0:/dev/sd<x>1:/dev/sd<y>2 osd1:/dev/sd<x>1:/dev/sd<y>2

Final steps

Now we need to copy the cluster configuration to all nodes and check the operational status of our Ceph deployment.

  1. Copy keys and configuration files, (replace mon0 osd0 osd1 with the name of your Ceph nodes)
    $ ceph-deploy admin mon0 osd0 osd1
  2. Ensure proper permissions for admin keyring
    $ sudo chmod +r /etc/ceph/ceph.client.admin.keyring
  3. Check the Ceph status and health
    $ ceph health
    $ ceph status

    If, at this point, the reported health of your cluster is HEALTH_OK, then most of the work is done. Otherwise, try to check the troubleshooting part of this tutorial.

Revert installation

There are useful commands to purge the Ceph installation and configuration from every node so that one can start over again from a clean state.

This will remove Ceph configuration and keys

ceph-deploy purgedata {ceph-node} [{ceph-node}]
ceph-deploy forgetkeys

This will also remove Ceph packages

ceph-deploy purge {ceph-node} [{ceph-node}]

Before getting a healthy Ceph cluster I had to purge and reinstall many times, cycling between the “Setup the cluster”, “Prepare OSDs and OSD Daemons” and “Final steps” parts multiple times, while removing every warning that ceph-deploy was reporting.

 

Vincenzo Pii

avatar

Vincenzo joined the ICCLab in March 2014 where he is working as a researcher in the Cloud Storage initiative.

Vincenzo obtained his Master’s Degree from the University of Pisa in March 2011 and has collected 3 years of working experience in the industry before joining ICCLab. At Intecs (Pisa), he has worked in the Telecommunications and Smart Systems research lab, participating in internal research activities, mainly related to M2M and IoT, and FP7 research projects, such as BETaaS. At TomTom (Eindhoven) Vincenzo has worked as a software engineer for the development of in-dash infotainment systems for cars, extensively adopting Scrum/Agile methodologies.

His current research activities are aimed at developing Cloud Storage systems with advanced technical features that can be suitable for application and adoption by industrial partners.

Cloud storage

Overview

Storage, together with computing and networking, is one of the fundamental parts of IaaS.

The research initiative on cloud storage at ICCLab, under the Infrastructure theme, focuses on the exploration of the limiting factors of the available storage systems, aiming at identifying new technologies and providing solutions that can be used to improve the efficiency of data management in cloud environments.

The need for advanced distributed architectures and software components allowing the deployment of secure, reliable, highly available and high-performing storage systems is clearly remarked by the fast growing rate of user-generated data. This trend sets challenging requirements for service and infrastructure providers to find efficient solutions for permanent data storage in their data centers.

About Cloud Storage Systems

A cloud storage system is typically obtained through a composition of software resources (running in a distributed environment), and a set of physical machines (i.e., servers), that exposes access to a logical layer of storage.

Cloud storage provides an abstract view of the multiple physical storage resources that it manages (these can be located across multiple servers, or even across different data centers) and it internally handles different layers of transparency that ensure reliability and performance.

The main concepts that are to be found in cloud storage systems are:

  • Data replication and reliability. Policies can be defined in such a way that copies of the same data are spread across different failure domains, to ensure availability and disaster recovery.
  • Data placement. A cloud storage system exposes a logical view of storage and internally handles how data is assigned to the available resources. This allows for e.g., striping data and improving access performance by using parallel accesses, or ensuring a proper load balancing between a set of nodes.
  • Availability. As a distributed system, cloud storage must not exhibit any single point of failure. This is usually achieved by introducing redundancy in hardware components and by implementing fail-over policies to recover from failures.
  • Performance. Concurrent accesses to data can improve data rates significantly as different portions of the same file or object can be provided by two different disks or nodes.
  • Geo-replication. A cloud storage system can replicate data in such a way that it is closer to where it is consumed (e.g., across data centers on different regions) to improve the access efficiency.

Objectives

  • Implement research ideas into working prototypes that can attract industrial interest
  • Obtain funding by participating in financed research projects
  • Produce and distribute our open source implementations
  • Keep and increase the reputation of the ICCLab in international contexts
  • Define a strong field of expertise in Distributed File Systems and software solutions for storage
  • Explore and implement clustered storage architectures

Research Topics

From an applied research perspective, the scenario of cloud computing and the growing demand for efficient data storage solutions, offers a ground where many areas and directions can be explored and evaluated.

Here at the ICCLab, the following aspects are currently being developed in the cloud storage initiative:

Contacts

Toni Zehnder

Toni Zehnder is currently in the sixth semester of his Bachelor of Engineering studies at ZHAW.

After a first qualification as plant layout designer he decided to move on in the academic area  and now studies Information Technology at ZHAW.

As part of his course of studies he joined the ICCLab as research assistant.  His research is dedicated to cloud computing infrastructure monitoring.

 

Bernhard Tellenbach

Bernhard TellenbachBernhard Martin Tellenbach is Associate Professor (Docent) at Zurich University of Applied Sciences. His interests are focused on IT security, coarsely ranging across network security, system security and network monitoring.

Prior to being appointed by ZHAW he was with ETH Zurich, University of Applied Sciences Rapperswil, Consecom AG, and ran his own IT consultancy business.  He was a visiting scholar at Microsoft Research Cambridge and Institut Eurécom.

His works have been published in several journals, and conferences. He serves as a technical reviewer for several international journals and conferences.

He is a member of the board of the Information Security Society Switzerland (ISSS) and the commission of experts of SwissICT, the largest professional association and voice of the Swiss IT sector.

Thomas Michael Bohnert


Thomas Michael Bohnert
is Professor at Zurich University of Applied Sciences and is the founder of the ICCLab and SPLab.

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Short Bio (Full details on LInkedIn)

His interests are enabling ICT systems, coarsely ranging across cloud computing infrastructures and platforms, cloud-native applications, as well as cloud-robotics and network function virtualization as specific application domains.

Prior to ZHAW he was with SAP Research (Technical Director) and SIEMENS Corporate Technology (Senior Researcher).

During his tenure he was visiting scholar at NEC Research (Germany), Tampere University of Technology and VTT Research (Finland), and Beijing University of Posts and Telecommunications (China). He completed his PhD at University of Coimbra (Portugal).

He owns a ICT consultancy and contributes to several expert groups of the European Commission on the future of ICT. The same applies to his role as regular proposal evaluator and project reviewer for the EC, the Swiss National Science Foundation, and the DAAD.

The Future Internet Public-Private-Partnership (www.fi-ppp.eu) appointment him as Deputy Chief Architect, presiding the FI-PPP Architecture Board and the FI-WARE project. He was technical coordinator of the Mobile Cloud Networking project and has a history of projects at European and national level.

He is founder of the IEEE Broadband Wireless Access Workshop (www.bwaws.org) and holds many project and conference chairs. From 2009-2011 he was on the steering board of the European Technology Platform Net!Works and co-chairs the EC DG NET FUTURES Future Internet Cluster. He acts as president of the Cloud Computing SIG of the Swiss Association of Computer Science as well as board member of the association at large.

His works have been published in several books, journals, and conferences. He serves as regional correspondent (Europe) for the IEEE Communication Magazine’s news section (GCN).

Contact: thomas.bohnert /at/ zhaw.ch

Franz Faul

After Franz Faul finished his apprenticeship in System Engineering at SwissRe he started working in the Middleware area. During his last Semester studying at the ZHAW, he is also working on his thesis in the ICC Cloud Lab. As the cloud is an emerging technology, the topic of data persistency is an interesting field of research.

His interest are mainly in security, network communication and development.

 

Florian Dudouet

Florian

Florian Dudouet is a researcher at the ICCLAB with a focus on performance measurement and optimization for cloud environments. His research interests are originally related to cloud interoperability but since being at the lab he had started working on Cloud Performance initially and is now currently part of the Cloud Orchestration initiative. He is currently working on the Mobile Cloud Networking FP7 project and the Solidna project.

Before joining the lab, Florian was a research engineer with Inria in Rennes, France. He worked on open-source software forges as a part of the Coclico French project then went on to work on cloud computing as a part of the Inria Myriads team where he participated in the Contrail FP7 project, working mainly on the cloud-middleware tool called Virtual Execution Platform. In the course of this work he used open-source standards such as OVF and CIMI and worked with virtualization tools such as OpenNebula and OpenStack.

Contact: florian.dudouet@zhaw.ch