Skip to content

Problem: Unknown how to tackle multiple writers #2

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
omarkj wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Problem: Unknown how to tackle multiple writers #2

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions 10/multiple_writers.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
# Goal

LMDB allows a single writer, which mean concurrent writes are not possible. The
goal of this document is to come up with a way to have multiple writers operate
on a subset of the PumpkinDB database using multiple LMDB volumes.

# Backstory and Reasoning

As things stand, PumpkinDB is backed by a single LMDB volume. This approach is
understandably to optimize for the development of PumpkinScript and other
important features such as locking, support for multiple writers etc. We
anticipate a time when a single writer will be a bottleneck to the throughput
of a PumpkinDB installation, hence the importance of coming up with approaches
to support multiple writers.

# Architecture

Instead of a single LMDB volume, a PumpkinDB installation can be configured to
be backed by multiple volumes, and writes sharded between them using a consistent
hash function (where keys are consistently hashed to the same volume). This would
make it known where a key should be looked up and where a key should be written,
the two most common operations in PumpkinDB.