Do allocate_clear no more than once per second

To lower the load on the database.

diff --git a/src/modules/rlm_sqlippool/rlm_sqlippool.c b/src/modules/rlm_sqlippool/rlm_sqlippool.c
index fb26097fc7152d2048e908e63b8d3800cb52a68f..a87cefecb482312739e46fbd6888bb587b1b32d9 100644 (file)
--- a/src/modules/rlm_sqlippool/rlm_sqlippool.c
+++ b/src/modules/rlm_sqlippool/rlm_sqlippool.c
@@ -49,6 +49,7 @@ typedef struct rlm_sqlippool_t {
           information in there
        */
                                /* Allocation sequence */
+       time_t last_clear;      /* so we only do it once a second */
        char *allocate_begin;   /* SQL query to begin */
        char *allocate_clear;   /* SQL query to clear an IP */
        char *allocate_find;    /* SQL query to find an unused IP */
@@ -498,6 +499,7 @@ static rlm_rcode_t mod_post_auth(void *instance, REQUEST *request)
        VALUE_PAIR *vp;
        rlm_sql_handle_t *handle;
        fr_ipaddr_t ipaddr;
+       time_t now;
 
        /*
         *      If there is a Framed-IP-Address attribute in the reply do nothing
@@ -524,9 +526,21 @@ static rlm_rcode_t mod_post_auth(void *instance, REQUEST *request)
                return RLM_MODULE_FAIL;
        }
 
-       DO(allocate_begin);
-       DO(allocate_clear);
-       DO(allocate_commit);
+       /*
+        *      Limit the number of clears we do.  There are minor
+        *      race conditions for the check, but so what.  The
+        *      actual work is protected by a transaction.  The idea
+        *      here is that if we're allocating 100 IPs a second,
+        *      we're only do 1 CLEAR per second.
+        */
+       now = time(NULL);
+       if (inst->last_clear != now) {
+               inst->last_clear = now;
+
+               DO(allocate_begin);
+               DO(allocate_clear);
+               DO(allocate_commit);
+       }
 
        DO(allocate_begin);