Matt try to change the default intervals:

<linkd-configuration threads="5" initial_sleep_time="3000"
snmp_poll_interval="3600000" discovery_link_interval="300000">

with:

<linkd-configuration threads="1" initial_sleep_time="3000"
snmp_poll_interval="600000" discovery_link_interval="300000">

threads = 1 so it is easy to debug and maybe the discovery link interval is not run while there are still
threads running snmpCollection

this will perform the snmp collection every 10 minutes and then after 5 minutes try to run (every 10 minutes in any way) the topology discovery

MacBook-Pro-di-Antonio-Russo:opennms antonio$ git diff
diff --git a/opennms-services/src/main/java/org/opennms/netmgt/linkd/DiscoveryLink.java b/openn
index cf6dfe1..9a2a8f4 100644
— a/opennms-services/src/main/java/org/opennms/netmgt/linkd/DiscoveryLink.java
+++ b/opennms-services/src/main/java/org/opennms/netmgt/linkd/DiscoveryLink.java
@@ -253,7 +253,10 @@ public final class DiscoveryLink implements ReadyRunnable {

protected void populateMacToAtInterface() {
LogUtils.debugf(this, "populateMacToAtInterface: using atNodes to populate macToAtinte

• for (final String macAddress : getLinkd().getAtInterfaces(getPackageName()).keySet())
  + final Map<String,List<AtInterface>> macs=getLinkd().getAtInterfaces(getPackageName());
  + if (macs== null || macs.keySet() == null )
  + return;
  + for (final String macAddress : macs.keySet()) {
  LogUtils.debugf(this, "populateMacToAtInterface: MAC %s now has atinterface refere
  for (final AtInterface at : getLinkd().getAtInterfaces(getPackageName()).get(macAd
  int nodeid = at.getNodeid();
  MacBook-Pro-di-Antonio-Russo:opennms antonio$ git commit -a
  [master 97af2c9] Fixed Exception in Linkd
  1 files changed, 4 insertions, 1 deletions
  MacBook-Pro-di-Antonio-Russo:opennms antonio$ git push
  Password:
  Counting objects: 21, done.
  Delta compression using up to 4 threads.
  Compressing objects: 100% (9/9), done.
  Writing objects: 100% (11/11), 1.03 KiB, done.
  Total 11 (delta 5), reused 0 (delta 0)
  To ssh://rssntn67@opennms.git.sourceforge.net/gitroot/opennms/opennms
  c2815d3..97af2c9 master -> master

The Linkd configuration i was using when I hit this.

eheh. Clearly cannot exists....
so I'll fix with a "control" to verify it is not null.

I'd like to get the linkd configuration and also the logs...

This method is the problem...

public Map<String, List<AtInterface>> getAtInterfaces(String packageName) {
return m_macToAtinterface.get(packageName);
}

could return null if the m_macToAtInterface has no key for packageName.....
but I remember that for every package there is a key....