# A Distributed File-Based Storage System for Improving High Availability of Space Weather Data
## 1 Introduction  
With the increase of numerous research efforts related to the space environment, the advancements of space technology greatly influence human life in the current era. One of the most important examples is the utilization of satellites for communication and navigation. Currently, space research has been conducted by many countries showing high seriousness by establishing a national space agency that intensively supports government programs in space science and technology development. Indonesia, represented by the National Institute of Aeronautics and Space [1], is one of the countries in the Association of Southeast Asian Nations (ASEAN) that is actively researching aeronautics developments and space weather activities. In space research, LAPAN (Indonesia National Institute of Aeronautics and Space) has an information system service that provides data, information, and forecasts related to space weather called Space Weather Information and Forecast Services (SWIFS). SWIFS is one of the space weather services approved as an IES member for the ASEAN region since 2016. The International Space Weather Services (ISES) is a collaborative network of space weather service, was established to coordinate, improvise, and deliver operational space weather services. The SWIFS website contents are daily analysis results by forecasters that include solar activity, geomagnetic activity,and ionospheric activity, as well as one-day or three-day forecasts at the weekend. Other essential information is also provided to the space weather user community, such as the current conditions on high-frequency radio communication propagation, the position error percentage for navigation, and the number of proton energies from the sun that impact satellites and high-frequency predictions [2]. SWIFIS researchers and forecasters conduct daily data analysis and processing to provide accurate information on the SWIFIS website for the user. For this reason, the data availability from space weather observation instruments is continuously updated to maintain information. At the background process, SWIFt5 are supported by the data storage system that collects the data from various instruments installed on observatory stations spread throughout areas in Indonesia. The daily information provided by SWIFt5 requires the data storage system to be continuously running well. The existing system implements the client-server hierarchy based on the centralized model. However, the process that has been running did not meet our expectations. The delay in data updating on the server is a significant issue and causes problems when researchers need the latest data, but the server is unable to provide it. For instance, the Canadian Advanced Digital Ionosonde (CADI), which is a special radar for studying ionized parts in the Ionosphere. Almost every day, its data from Bialk observatory that formed every 15-min gets delayed more than 30 min when synchronized to the Bandung server. This is due to the centralized model that is implemented in the current system. Each time a personal computer (PC) collects data from the instrument, it sends the data to a server located in the observatory stations. The rapid growth of data provides great benefits for its users; thus, data is becoming a valuable asset and must, therefore, be properly maintained [3; 4]. In data production, LAPAN has eight observatory stations (hereafter referred to as sites) spread in different islands and one central data center (Figure 1). Researchers in Bandung, where the data center is located, need actual data for data processing and making forecasts to update the SWIFt5 website. Problems arise when servers in Bandung must provide the latest data while the site server is down. The researchers have trouble conducting their research, and the renewal of information on the SWIFt5 website is hampered. Centralized data management is a conventional method to store data that relies on one single server.