Reducing JSON API's memory usage

Questions
1

Hi all,

Is there a way to reduce the memory footprint of the JSON API?

Our dev environment has a three participant setup using a single Canton container and three JSON APi containers and the memory required is becoming too burdensome. Canton takes about ~2.5 GBs which is fine but each of the JSON API containers takes ~1.5 GBs which leaves very little room for the rest of our stack.

We’ve been working around this by bumping Docker memory allocation from 8 GBs to10 GBs but that’s steadily becoming insufficient as we continue development.

Is there anything we can do to cut down on memory?

The JSON API conf we’re using:

{
  server {
    address = "0.0.0.0"
    port = ${HTTP_PORT}
  }

  ledger-api {
    address = ${LEDGER_HOST}
    port = ${LEDGER_PORT}
  }

  metrics {
    //Start a metrics reporter. Must be one of "console", "csv:///PATH", "graphite://HOST[:PORT][/METRIC_PREFIX]", or "prometheus://HOST[:PORT]".
    reporter = "console"
    //Set metric reporting interval , examples : 1s, 30s, 1m, 1h
    reporting-interval = 1h
  }
}

The Dockerfile

FROM amazoncorretto:19.0.2 as base

FROM base as build

RUN mkdir /jars && curl -L -o /jars/http-json.jar https://github.com/digital-asset/daml/releases/download/v2.5.5/http-json-2.5.5.jar

FROM base as release

RUN yum upgrade -y \
    && yum install -y shadow-utils gettext \
    && yum clean all \
    && groupadd --gid 1002 --system app \
    && useradd --uid 1001 --gid app --system app

RUN mkdir /app && chown app:app /app

USER app

COPY --chown=app:app --from=build /jars /app/jars
COPY --chown=app:app ./json-api-app.conf /app/json-api-app.conf
COPY --chown=app:app ./docker-entrypoint.sh /


ENV LEDGER_HOST localhost
ENV LEDGER_PORT 6865
ENV HTTP_PORT 7575
ENV DB_SCHEMA_NAME postgres
ENV LOG_LEVEL INFO

ENTRYPOINT ["sh", "docker-entrypoint.sh"]

Entrypoint

#!/bin/sh
cat /app/json-api-app.conf | envsubst > /app/json-api-app.with-env.conf

echo "Using config file: "
cat /app/json-api-app.with-env.conf

exec java \
  -jar /app/jars/http-json.jar \
  --config /app/json-api-app.with-env.conf \
  --log-level $LOG_LEVEL \
  --log-encoder json
2

Disregard - fixed this by consolidating HTTP JSON containers and participants.

We “emulate” a three participant setup by making sure each participant has its own party. In deployed environments, we still use multiple containers.