Iacovos Kolokasis

Iacovos Kolokasis

Graduate Research Assistant

CARV, ICS-FORTH

Biography

I am a 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). My research lies at the intersection of managed runtimes, memory systems, and operating systems. My doctoral research focuses on scaling managed heaps on fast storage devices, such as NVMe SSDs, to reduce DRAM usage in managed big data applications, primarily through work on the OpenJDK HotSpot and G1 garbage collector, including heap resizing, memory partitioning, and tiered heap management.

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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