Iacovos Kolokasis

Iacovos Kolokasis

Graduate Research Assistant

CARV, ICS-FORTH

Biography

I am a 4th-year PhD student in the Computer Science Department at the University of Crete, advised by Prof. Angelos Bilas, Prof. Polyvios Pratikakis, and Prof. Shoaib Akram. I am also a graduate research assistant in the Institute of Computer Science (ICS) at the Foundation of Research and Technology - Hellas (FORTH). I received my Bachelor’s and Master’s degrees in Computer Science from the University of Crete in 2017 and 2020, respectively. My main research interests fall at the intersection of managed programming languages and runtimes, memory, and storage systems. My work focuses on exploiting emerging non-volatile memories and fast block-addressable storage devices to improve heap efficiency in managed languages for data warehouse workloads, such as big-data analytics frameworks. My recent work resolves the tension between garbage collection and serialization/deserialization by providing a separate scanless managed heap over storage devices. It eliminates both garbage collection and serialization overheads without imposing any language restrictions.

I am honored that my current work, during my doctoral studies, was awarded with the Meta Research PhD Fellowship (2022-2024) and the State Scholarship Foundation of Cyprus (2020-2023).

Interests
  • Managed Languages and Runtimes Systems
  • Garbage Collection
  • Memory Systems
Education
  • PhD in Computer Science, 2021-present

    University of Crete, Greece

  • MSc in Computer Science, 2020

    University of Crete, Greece

  • BSc in Computer Science, 2017

    University of Crete, Greece

Experience

 
 
 
 
 
CARV, ICS-FORTH
Graduate Research Assistant
January 2021 – Present Heraklion, Greece
We desing and implement TeraHeap, an extention of OpenJDK JVM that uses a primary managed heap in DRAM and a second managed heap over NVMe SSD. TeraHeap avoids GC scans over objects in the second managed heap.
 
 
 
 
 
Computer Science Department, UoC
Teaching Assistant
September 2017 – Present Heraklion, Greece

Responsibilities include:

  • Marking assignments and exams
  • Give tutorials
  • Answering student’s questions
  • Projects and assignments co-design with the professor and another TA
 
 
 
 
 
Huawei Research Center
PhD Intern Research Assistant
June 2019 – September 2019 Munich, Germany
We extend OpenJDK to use tow managed heaps: a primary heap allocated over DRAM and a second heap allocated over a remote Key/Value store.
 
 
 
 
 
SAP
Intern Research Assistant
June 2019 – September 2019 Walldorf, Germany
Improve the data siructure of the syntax tree of the SQL parser.
 
 
 
 
 
CARV, ICS-FORTH
Undergraduate Research Assistant
January 2017 – August 2017 Heraklion, Greece
I worked on graph analysis and management on distributed systems and examined how different partition strategies determine the performance of distributed-graph-processing engines, using characterization metrics. During my work, I used Spark-GraphX and Giraph.

Projects

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TeraHeap: Reducing Memory Pressure in Managed Big Data Frameworks
TeraHeap extends the JVM to use a second, high-capacity heap over a fast storage device that coexists with the regular heap. TeraHeap provides direct access to objects on the second heap. It also reduces GC cost by fencing the garbage collector from scanning the second heap. TeraHeap leverages frameworks’ property of choosing specific objects for off-heap placement and offers frameworks a hint-based interface for moving such objects to the second heap.

Recent & Upcoming Affiliated Conferences and Journals

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