DCA Hardened In-Memory Cache for Memcached — Support & Quick Start

At a glance

Status	Live on Oracle Cloud Marketplace
Version	1.6.9
Platform	Oracle Linux 9
Ports open in the host firewall	SSH (22/tcp), 11211/tcp
Category	Databases
Upstream licence	BSD-3-Clause
Pricing	Pay-as-you-go software fee per OCPU-hour, billed by Oracle on your OCI invoice — see the listing's Pricing tab

Quick start

This is the listing's usage information, verbatim.

After launch:

1. Connect over SSH as the opc user with the key you supplied at launch:

   ssh opc@<public-ip>

2. Memcached runs as a systemd service on TCP 11211, bound to loopback, UDP disabled. Check status:

   sudo systemctl status memcached

3. Smoke-test from the instance:

   echo stats | nc 127.0.0.1 11211 | head

4. Memcached has NO authentication. Expose it only inside a private subnet to trusted clients: edit /etc/sysconfig/memcached and change the -l option to the instance's private IP (keep -U 0 — UDP stays off), then:

   sudo systemctl restart memcached

   Restrict TCP 11211 in your VCN security list to the application tier's CIDR. Never expose 11211 to the internet.

5. Size the cache to the shape you launched: raise CACHESIZE (in MB) in /etc/sysconfig/memcached to roughly 60-70% of instance memory on a dedicated cache node, and raise MAXCONN if your client fleet is large. Restart to apply.
6. Point your application's memcached client at <private-ip>:11211. Multiple cache nodes scale horizontally — clients hash keys across the pool; launch more instances of this image and list them all in the client configuration.

The image is CVE-patched at build time. Apply ongoing updates with:

sudo dnf -y update

What the image provides

• Memcached 1.6.9 from the Oracle Linux 9 AppStream repository — no third-party repo is added to the image, and Oracle carries the security-errata stream for it — running as a dedicated unprivileged service.
• Safe-by-default network posture for a service that has no authentication: bound to loopback until you expose it deliberately, and UDP disabled outright (the protocol behind the 2018 memcached amplification attacks). Only TCP 11211 is declared in the host firewall.
• Sensible starting limits (4096 connections, 1 GB cache) with one file to edit — /etc/sysconfig/memcached — to size the cache to your shape's memory.
• A locked-down systemd service and security hardening aligned to the Oracle Cloud Marketplace image standards: SELinux enforcing, host firewall default-deny with only SSH and 11211 permitted, no account with a usable password, no stray keys, and the image fully patched at build time.

Still stuck?

Email support@dcassociatesgroup.com (response within 1 business day) or use the contact form. Include the listing name, your OCI region, the instance OCID and the output of sudo journalctl -u <service> -n 100 for the unit named in the quick start.