ctdb: Add "home_nodes" file to deterministic IP allocation

With a file "home_nodes" next to "public_addresses" you can assign
public IPs to specific nodes when using the deterministic allocation
algorithm. Whenever the "home node" is up, the IP address will be
assigned to that node, independent of any other deterministic
calculation. The line

192.168.21.254 2

in the file "home_nodes" assigns the IP address to node 2. Only when
node 2 is not able to host IP addresses, 192.168.21.254 undergoes the
normal deterministic IP allocation algorithm.

Signed-off-by: Volker Lendecke <vl@samba.org>
add home_nodes
Reviewed-by: Ralph Boehme <slow@samba.org>
Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Tue Oct 10 14:17:19 UTC 2023 on atb-devel-224

diff --git a/ctdb/doc/ctdb-tunables.7.xml b/ctdb/doc/ctdb-tunables.7.xml
index 725c781e47ef19e6180056441ae71a7dcaa8d12a..e4f7ce0b96ace3b0a4f1501d18a02840f35291c1 100644 (file)
--- a/ctdb/doc/ctdb-tunables.7.xml
+++ b/ctdb/doc/ctdb-tunables.7.xml
@@ -283,6 +283,17 @@ MonitorInterval=20
              with care when addresses are defined across multiple
              networks.
            </para>
+           <para>
+             You can override automatic the "home" node allocation by
+             creating a file "home_nodes" next to the
+             "public_addresses" file. As an example the following
+             "home_nodes" file assigns the address 192.168.1.1 to
+             node 0 and 192.168.1.2 to node 2:
+           </para>
+           <screen format="linespecific">
+             192.168.1.1 0
+             192.168.1.2 2
+            </screen>
          </listitem>
        </varlistentry>
        <varlistentry>

diff --git a/ctdb/server/ipalloc_deterministic.c b/ctdb/server/ipalloc_deterministic.c
index 64c6b4cf2626f853144d83487b8de0f4412df59f..43680ba5c2fcde87f36d200d6a59ec7c042627b7 100644 (file)
--- a/ctdb/server/ipalloc_deterministic.c
+++ b/ctdb/server/ipalloc_deterministic.c
@@ -24,11 +24,117 @@
 
 #include "lib/util/debug.h"
 #include "common/logging.h"
+#include "common/path.h"
+
+#include "protocol/protocol_util.h"
+#include "lib/util/smb_strtox.h"
+#include "lib/util/memory.h"
 
 #include "server/ipalloc_private.h"
 
+struct home_node {
+       ctdb_sock_addr addr;
+       uint32_t pnn;
+};
+
+static struct home_node *ipalloc_get_home_nodes(TALLOC_CTX *mem_ctx)
+{
+       char *line = NULL;
+       size_t len = 0;
+       char *fname = NULL;
+       FILE *fp = NULL;
+       struct home_node *result = NULL;
+
+       fname = path_etcdir_append(mem_ctx, "home_nodes");
+       if (fname == NULL) {
+               goto fail;
+       }
+
+       fp = fopen(fname, "r");
+       if (fp == NULL) {
+               goto fail;
+       }
+       TALLOC_FREE(fname);
+
+       while (true) {
+               size_t num_nodes = talloc_array_length(result);
+               char *saveptr = NULL, *addrstr = NULL, *nodestr = NULL;
+               struct home_node hn = {
+                       .pnn = CTDB_UNKNOWN_PNN,
+               };
+               struct home_node *tmp = NULL;
+               ssize_t n = 0;
+               int ret;
+
+               n = getline(&line, &len, fp);
+               if (n < 0) {
+                       if (!feof(fp)) {
+                               /* real error */
+                               goto fail;
+                       }
+                       break;
+               }
+               if ((n > 0) && (line[n - 1] == '\n')) {
+                       line[n - 1] = '\0';
+               }
+
+               addrstr = strtok_r(line, " \t", &saveptr);
+               if (addrstr == NULL) {
+                       continue;
+               }
+               nodestr = strtok_r(NULL, " \t", &saveptr);
+               if (nodestr == NULL) {
+                       continue;
+               }
+
+               ret = ctdb_sock_addr_from_string(addrstr, &hn.addr, false);
+               if (ret != 0) {
+                       DBG_WARNING("Could not parse %s: %s\n",
+                                   addrstr,
+                                   strerror(ret));
+                       goto fail;
+               }
+
+               hn.pnn = smb_strtoul(nodestr,
+                                    NULL,
+                                    10,
+                                    &ret,
+                                    SMB_STR_FULL_STR_CONV);
+               if (ret != 0) {
+                       DBG_WARNING("Could not parse \"%s\"\n", nodestr);
+                       goto fail;
+               }
+
+               tmp = talloc_realloc(mem_ctx,
+                                    result,
+                                    struct home_node,
+                                    num_nodes + 1);
+               if (tmp == NULL) {
+                       goto fail;
+               }
+               result = tmp;
+               result[num_nodes] = hn;
+       }
+
+       fclose(fp);
+       fp = NULL;
+       return result;
+
+fail:
+       if (fp != NULL) {
+               fclose(fp);
+               fp = NULL;
+       }
+       SAFE_FREE(line);
+       TALLOC_FREE(fname);
+       TALLOC_FREE(result);
+       return NULL;
+}
+
 bool ipalloc_deterministic(struct ipalloc_state *ipalloc_state)
 {
+       struct home_node *home_nodes = ipalloc_get_home_nodes(ipalloc_state);
+       size_t num_home_nodes = talloc_array_length(home_nodes);
        struct public_ip_list *t;
        int i;
        uint32_t numnodes;
@@ -42,7 +148,26 @@ bool ipalloc_deterministic(struct ipalloc_state *ipalloc_state)
        */
 
        for (i = 0, t = ipalloc_state->all_ips; t!= NULL; t = t->next, i++) {
+               size_t j;
+
                t->pnn = i % numnodes;
+
+               for (j = 0; j < num_home_nodes; j++) {
+                       struct home_node *hn = &home_nodes[j];
+
+                       if (ctdb_sock_addr_same_ip(&t->addr, &hn->addr)) {
+
+                               if (hn->pnn >= numnodes) {
+                                       DBG_WARNING("pnn %" PRIu32
+                                                   " too large\n",
+                                                   hn->pnn);
+                                       break;
+                               }
+
+                               t->pnn = hn->pnn;
+                               break;
+                       }
+               }
        }
 
        /* IP failback doesn't make sense with deterministic
@@ -60,5 +185,7 @@ bool ipalloc_deterministic(struct ipalloc_state *ipalloc_state)
 
        /* No failback here! */
 
+       TALLOC_FREE(home_nodes);
+
        return true;
 }

diff --git a/ctdb/tests/UNIT/takeover/det.004.sh b/ctdb/tests/UNIT/takeover/det.004.sh
new file mode 100755 (executable)
index 0000000..3673cc1
--- /dev/null
+++ b/ctdb/tests/UNIT/takeover/det.004.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+. "${TEST_SCRIPTS_DIR}/unit.sh"
+
+setup_ctdb_base "$CTDB_TEST_TMP_DIR" "ctdb-etc"
+
+define_test "3 nodes, all healthy with home_nodes"
+
+home_nodes="$CTDB_BASE"/home_nodes
+
+cat > "$home_nodes" <<EOF
+192.168.21.254 2
+192.168.20.251 1
+EOF
+
+required_result <<EOF
+${TEST_DATE_STAMP}Deterministic IPs enabled. Resetting all ip allocations
+192.168.21.254 2
+192.168.21.253 1
+192.168.21.252 2
+192.168.20.254 0
+192.168.20.253 1
+192.168.20.252 2
+192.168.20.251 1
+192.168.20.250 1
+192.168.20.249 2
+EOF
+
+simple_test 0,0,0 <<EOF
+192.168.20.249 1
+192.168.20.250 1
+192.168.20.251 1
+192.168.20.252 1
+192.168.20.253 1
+192.168.20.254 1
+192.168.21.252 1
+192.168.21.253 1
+192.168.21.254 1
+EOF
+
+rm "$home_nodes"

diff --git a/ctdb/tests/UNIT/takeover/det.005.sh b/ctdb/tests/UNIT/takeover/det.005.sh
new file mode 100755 (executable)
index 0000000..aaa5e0f
--- /dev/null
+++ b/ctdb/tests/UNIT/takeover/det.005.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+
+. "${TEST_SCRIPTS_DIR}/unit.sh"
+
+setup_ctdb_base "$CTDB_TEST_TMP_DIR" "ctdb-etc"
+
+define_test "3 nodes, 2 healthy with home_nodes"
+
+home_nodes="$CTDB_BASE"/home_nodes
+
+cat > "$home_nodes" <<EOF
+192.168.21.254 2
+192.168.20.251 1
+EOF
+
+required_result <<EOF
+${TEST_DATE_STAMP}Deterministic IPs enabled. Resetting all ip allocations
+${TEST_DATE_STAMP}Unassign IP: 192.168.21.253 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.253 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.251 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.250 from 1
+192.168.21.254 2
+192.168.21.253 0
+192.168.21.252 2
+192.168.20.254 0
+192.168.20.253 0
+192.168.20.252 2
+192.168.20.251 0
+192.168.20.250 0
+192.168.20.249 2
+EOF
+
+simple_test 0,2,0 <<EOF
+192.168.20.249 0
+192.168.20.250 1
+192.168.20.251 2
+192.168.20.252 0
+192.168.20.253 1
+192.168.20.254 2
+192.168.21.252 0
+192.168.21.253 1
+192.168.21.254 2
+EOF
+
+rm "$home_nodes"

diff --git a/ctdb/tests/UNIT/takeover/det.006.sh b/ctdb/tests/UNIT/takeover/det.006.sh
new file mode 100755 (executable)
index 0000000..504c430
--- /dev/null
+++ b/ctdb/tests/UNIT/takeover/det.006.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+. "${TEST_SCRIPTS_DIR}/unit.sh"
+
+setup_ctdb_base "$CTDB_TEST_TMP_DIR" "ctdb-etc"
+
+define_test "3 nodes, 1 healthy with home_nodes"
+
+home_nodes="$CTDB_BASE"/home_nodes
+
+cat > "$home_nodes" <<EOF
+192.168.21.254 2
+192.168.20.251 1
+EOF
+
+required_result <<EOF
+${TEST_DATE_STAMP}Deterministic IPs enabled. Resetting all ip allocations
+${TEST_DATE_STAMP}Unassign IP: 192.168.21.253 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.254 from 0
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.253 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.251 from 1
+${TEST_DATE_STAMP}Unassign IP: 192.168.20.250 from 1
+192.168.21.254 2
+192.168.21.253 2
+192.168.21.252 2
+192.168.20.254 2
+192.168.20.253 2
+192.168.20.252 2
+192.168.20.251 2
+192.168.20.250 2
+192.168.20.249 2
+EOF
+
+simple_test 2,2,0 <<EOF
+192.168.20.249 0
+192.168.20.250 1
+192.168.20.251 2
+192.168.20.252 0
+192.168.20.253 1
+192.168.20.254 2
+192.168.21.252 0
+192.168.21.253 1
+192.168.21.254 2
+EOF
+
+rm "$home_nodes"