Contributors: N. Rahpoe (DWD)
Issued by: Nabiz Rahpoe
Date: 02/11/2020
Ref: C3S_D312b_Lot1.2.3.7-v1.1_202102_SQAD_TCWV_SSMIS_TCDR+ICDR_v1.1.1
Official reference number service contract: 2018/C3S_312b_Lot1_DWD/SC1
History of modifications
List of datasets covered by this document
Acronyms
General definitions
Scope of the document
This document describes the systems used for delivering of Total Column Water Vapour to the Climate Data Store (CDS) of the Copernicus Climate Change Service (C3S). The dataset is based on SSM/I and SSMIS sensor's measurements retrieved with the HOAPS 4.0 algorithm covering TCDR & ICDR. Interfaces to external data, the infrastructure for data processing (if applicable), and the interface to the CDS are outlined. Information about new data cycles and reprocessing is also provided in this document. Internal procedures for managing and communicating system maintenance and for user support are described.
Executive summary
The dataset is made accessible to the CDS via DWD's webserver at https://c3s.satproj.klima.dwd.de/data/ and can be ordered via HTTP protocol. The data are password-protected (login details are provided directly to the CDS team with data delivery).
Respective outages will be kept to a minimum and, whenever possible, communicated to C3S in advance.
We provide user support for queries relating to our products when forwarded to us by C3S (see Chapter 5 User Support).
1. System overview
1.1 System elements and interfaces
The product of the CM SAF TCWV SSM/I SSMIS HOAPS 4.0 dataset (TCDR) on total column water vapour were downloaded via the CM SAF Web User Interface and copied to the webserver hosted by DWD (see Section 1.2.3).
The ICDR (2015-2020), based on the same algorithm as TCDR (1988-2014) are an extension of the previous time series, and has been produced within the framework of C3S project, and are not available on CMSAF web page.
1.1.1 Delivery of the data to C3S
The dataset is made accessible to the CDS via DWD's webserver at https://c3s.satproj.klima.dwd.de/data/ and can be ordered via HTTP protocol. The data are password-protected (login details are provided directly to the CDS team with data delivery). This allows automated access to the files, e.g. via scripts handling the delivery chain of an order in the CDS from the server to the user.
We aim for a 99% availability of the data server, with 95% of the data transactions happening at a rate of 10 Mbit/s or faster.
1.2 Hardware and data server system
1.2.1 Computing infrastructure
The ICDRs have been produced within the HOAPS CMSAF group at DWD. The computing infrastructure includes the Linux machines (CentOS 7) for processing of L2 & L3 datasets of monthly means and 6-hourly daily composites. The processor runs on a server with multi node parallel machines with several cores.
1.2.2 Back-up
There are auxiliary & input data used within the L2 processor that comes from external sources, where back-ups outside our responsibilities are maintained. The script to generate the data and the metadata is automated. It is backed up by the IT-department of the DWD. In the case of data corruption or loss on the data server, which serves as an interface to the CDS, the input data can be downloaded from their source and regenerated using the automated script. The estimated time needed for the full recovery of the data is 3 hours.
1.2.3 Webserver at DWD
DWD hosts the webserver (CentOs Linux) that can be accessed from outside the DWD firewall via HTTP. Monitoring of server availability is routinely performed using Nagios IT Infrastructure Monitoring Tool. The check is performed every 60 second and if the data on the webserver are unavailable, an automatic email notification is issued.
Preliminary analysis of the required disk space for data sets provided by DWD within C3S_312b_Lot1 necessary disk space shows that the quota on the data server dedicated to DWD's efforts within C3S_312b_Lot1 will not be exceeded.
2. Upgrade cycle implementation procedure
Not applicable
3. Procedures for reprocessing CDRs
Not applicable
4. System maintenance and system failures
In general, any issues with IT infrastructure that either delays delivery of data or impedes data access via the CDS will be documented in the Quarterly Reports.
4.1 Interfaces to external data
This section discusses treatment of delays at interfaces to external data sources.
4.1.1 Brokered CDRs
It is beyond the scope of our responsibility to safeguard the stability of services and data servers of external providers. If we become aware of issues at their end that will impede the timely delivery of brokered data, we will notify C3S.
4.2 Production of ICDR data sets
The ICDR data set has been produced at DWD within the framework of C3S project. Any updates or inconsistencies can be addressed immediately.
4.3 Interface to the CDS
This section discusses maintenance and outages of the data server hosting the files for access through the CDS.
4.3.1 Planned maintenance
Planned outages of the data server on which the CDS accesses the files are kept to a minimum. However, software updates may become necessary, or hardware may need to be maintained or replaced. Such planned outages will be communicated to the CDS as early as possible. Respective notifications will be issued by DWD's IT department and delivered to the DWD-based members of the Service Management Team of C3S_312b_Lot1, who will ensure prompt passing on to the CDS. We do not expect to contact users of data sets submitted by us directly, but only through this communication to CDS.
We are open to requests by C3S to schedule dates on which no planned maintenance involving an outage should be carried out. Although a respective commitment by the IT department cannot be guaranteed, we always strive to respect such requests.
4.3.2 Unplanned outages
Unexpected system outages will be treated according to internal regulations and procedures at DWD's IT department. This involves notification of the DWD-based members of the Service Management Team, who will in turn notify C3S of the outage as quickly as possible. The IT department will resolve the issue according to their procedures and notify C3S, again via the Service Management Team.
5. User support
5.1 Enquiries
The user (customer) has the possibility to browse and search in the Copernicus Knowledge Base (CKB) (CAMS and C3S Knowledge Base (CKB)) or the Copernicus Climate Data Store desk (https://cds.climate.copernicus.eu/contact-us). This is known as the level-0 process of User Support.
Figure 1: The schematic of Copernicus User Support (Copernicus User Support Handbook, V2.1)
Contact and User Support process on JIRA service desk
If the level-0 support fails to answer the user's query, they may then make a request, which is sent to the Copernicus User Support (CUS) Service team at ECMWF. These (level-1) requests will be handled within 8 hours.
For any scientific and specialist enquiries that cannot be answered by the CUS team at ECMWF or addressed by the Copernicus Knowledge Base, the request will be forwarded to the Copernicus User Support Specialists (level-2).
Enquiries forwarded to the Copernicus User Support Specialist team will be acknowledged within 3 working days (target 100%) and a notification sent to the user. This step is handled on the JIRA 1 Service Desk established at ECMWF for the current project. In case of specific scientific issues, the enquiries will be channeled to the ECV and data specialist of the C3S2_312a_Lot1 project and should be resolved within 3 working weeks (target 85%). In case of brokered datasets, the data specialist may choose to contact the responsible team at the provider level if they cannot resolve the issue on their own. In each yearly quarter, we aim for User Support satisfaction scoring 3 in 90% of all voluntary based feedbacks by users, with 1 (very unsatisfied) to 5 (very satisfied). We will also list the number of tickets raised by users on the JIRA system in the Quarterly Report.
- JIRA: Project management software tool created by Atlassian company ↩
