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dCache clinet access protocol DCAP

Basic definitions

DCAP client - door protocol:

is line based. Each line is expected to be sent and received atomicly.
The line can only contain ASCII characters.
A line consists of tokens. Tokens are separated by at least one blank character. Tokens containing blanks have to be quoted.

[DEFAULT]
enabled_share_backends = dcache
enabled_share_protocols = NFS

[dcache]
share_backend_name = dCache
driver_handles_share_servers = False
share_driver = manila.share.drivers.dcache.dcache.DCacheShareDriver
dcache_api_url = https://dcache-lab007:3333

Working hard to solve complex problems
Developing distributed (storage) systems
Contributing to many OSS projects
Consuming coffee ☕
Java, C, Go, Python ... UNIX

Fun with Pinned gists

Reporting dCache CPU & Memory usage with metricbeats

Pre-requisites

Download and install Metricbeat. Use metricbeat-oss package, if you don't have xpack
Download Jolokia's JVM agent

Enable Jolokia JVM agent

Overview

The Mover-Client connection is a binary connection which, TCP wise, may be initiated by either parties.
The mover starts the communication by sending the Mover HELLO BLOCK (see below).
All subsequent commands are initiated by the client.
The protocol is limited to synchronous request-reply communication. Therefore a command can only be issued after the previous command was completed.
The connection can either be in Command Mode, which is the initial mode, or in Data Transfer Mode.
Each command has to be acknowledged immediately by an REQUEST ACK. The REQUEST ACK reports the request state and in some cases additional, request dependent arguments . (e.g. LOCATE)
If the REQUEST ACK indicates success, the connection switches to Data Transfer Mode for READ and WRITE requests.
In Data Transfer Mode the data is send in DATA CHAINS ( see below).

	#
	# tuned configuration for dcache pools
	#

	[main]
	summary=tuned configuration for dcache pools

	[cpu]
	governor=performance
	energy_perf_bias=performance

	# https://docs.docker.com/compose/yml/
	# Each service defined in docker-compose.yml must specify exactly one of
	# image or build. Other keys are optional, and are analogous to their
	# docker run command-line counterparts.
	#
	# As with docker run, options specified in the Dockerfile (e.g., CMD,
	# EXPOSE, VOLUME, ENV) are respected by default - you don't need to
	# specify them again in docker-compose.yml.
	#
	service_name:

	import java.nio.ByteBuffer;

	public class Hexdump {

	public static void dumphex(long offset, ByteBuffer buffer) {

	byte[] chunk = new byte[16];

	while(buffer.hasRemaining()) {