kofemann

• 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

kofemann

[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

kofemann

kofemann

import java.nio.ByteBuffer;

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

        byte[] chunk = new byte[16];

        while(buffer.hasRemaining()) {

kofemann

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.

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# 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:

kofemann

#
# tuned configuration for dcache pools
#

[main]
summary=tuned configuration for dcache pools

[cpu]
governor=performance
energy_perf_bias=performance

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#
# tuned configuration
# /etc/tuned/virtual-guest-nfs-client/tuned.conf
#

[main]
summary=Optimize for running inside a virtual guest
include=throughput-performance

[sysctl]

kofemann

import com.sun.btrace.annotations.*;
import static com.sun.btrace.BTraceUtils.*;

@BTrace
public class PnfsHandler {

  @OnMethod(
    clazz="diskCacheV111.util.PnfsHandler",
    method="clearCacheLocation"
  )

kofemann

dCache code guideline

Spaces vs Tabs

dCache projects uses four (4) spaces indention. Some historic code still have mixed style. However, the newly written code must stick to spaces.