[5264] Improved logging in HostMgr for most common queries.

src/lib/dhcpsrv/host_mgr.cc

-// Copyright (C) 2014-2016 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2014-2017 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -131,9 +131,33 @@ HostMgr::get4(const SubnetID& subnet_id,
     ConstHostPtr host = getCfgHosts()->get4(subnet_id, identifier_type,
                                             identifier_begin, identifier_len);
     if (!host && alternate_source_) {
+
+        LOG_DEBUG(hosts_logger, HOSTS_DBG_TRACE,
+                  HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER)
+            .arg(subnet_id)
+            .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                           identifier_len));
+
         host = alternate_source_->get4(subnet_id, identifier_type,
                                        identifier_begin, identifier_len);
+
+        if (host) {
+            LOG_DEBUG(hosts_logger, HOSTS_DBG_RESULTS,
+                      HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER_HOST)
+                .arg(subnet_id)
+                .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                               identifier_len))
+                .arg(host->toText());
+
+        } else {
+            LOG_DEBUG(hosts_logger, HOSTS_DBG_RESULTS,
+                      HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER_NULL)
+                .arg(subnet_id)
+                .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                               identifier_len));
+        }
     }
+
     return (host);
 }
 
@@ -193,8 +217,33 @@ HostMgr::get6(const SubnetID& subnet_id,
     ConstHostPtr host = getCfgHosts()->get6(subnet_id, identifier_type,
                                             identifier_begin, identifier_len);
     if (!host && alternate_source_) {
+
+        LOG_DEBUG(hosts_logger, HOSTS_DBG_TRACE,
+                  HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER)
+            .arg(subnet_id)
+            .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                           identifier_len));
+
+
         host = alternate_source_->get6(subnet_id, identifier_type,
                                        identifier_begin, identifier_len);
+
+        if (host) {
+            LOG_DEBUG(hosts_logger, HOSTS_DBG_RESULTS,
+                      HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER_HOST)
+                .arg(subnet_id)
+                .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                               identifier_len))
+                .arg(host->toText());
+
+        } else {
+            LOG_DEBUG(hosts_logger, HOSTS_DBG_RESULTS,
+                      HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER_NULL)
+                .arg(subnet_id)
+                .arg(Host::getIdentifierAsText(identifier_type, identifier_begin,
+                                               identifier_len));
+        }
+
     }
     return (host);
 }

src/lib/dhcpsrv/hosts_messages.mes

-# Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+# Copyright (C) 2015-2017 Internet Systems Consortium, Inc. ("ISC")
 #
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -146,6 +146,34 @@ host connected to the specific subnet and identified by the HW address
 or DUID, and it is starting to search for this host in the alternate
 host data source.
 
+% HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER get one host with IPv4 reservation for subnet id %1, identified by %2
+This debug message is issued when starting to retrieve a host holding
+IPv4 reservation, which is connected to a specific subnet and
+is identified by a specific unique identifier.
+
+% HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER_HOST using subnet id %1 and identifier %2, found host: %3
+This debug message includes the details of a host returned by an
+alternate hosts data source using a subnet id and specific host
+identifier.
+
+% HOSTS_MGR_ALTERNATE_GET4_SUBNET_ID_IDENTIFIER_NULL host not found using subnet id %1 and identifier %2
+This debug message is issued when no host was found using the specified
+subnet id and host identifier.
+
+% HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER get one host with IPv6 reservation for subnet id %1, identified by %2
+This debug message is issued when starting to retrieve a host holding
+IPv4 reservation, which is connected to a specific subnet and
+is identified by a specific unique identifier.
+
+% HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER_HOST using subnet id %1 and identifier %2, found host: %3
+This debug message includes the details of a host returned by an
+alternate hosts data source using a subnet id and specific host
+identifier.
+
+% HOSTS_MGR_ALTERNATE_GET6_SUBNET_ID_IDENTIFIER_NULL host not found using subnet id %1 and identifier %2
+This debug message is issued when no host was found using the specified
+subnet id and host identifier.
+
 % HOSTS_MGR_ALTERNATE_GET6_PREFIX trying alternate source for host using prefix %1/%2
 This debug message is issued when the Host Manager doesn't find the
 host connected to the specific subnet and having the reservation for