Avoid full table scan for dispatcher table using db_redis as backend

[joelsdc]

Description

I'm trying to avoid getting this warning:

Nov 22 20:36:35 test COPS[25531]: WARNING: db_redis [redis_dbase.c:1098]: db_redis_perform_query(): performing full table scan on table 'dispatcher' while performing query

Troubleshooting

Having:

modparam("db_redis", "keys", "version=entry:table_name")
modparam("db_redis", "keys", "dispatcher=entry:id")

And debug logs showing the key being found:

Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:200]: db_redis_print_all_tables():   table dispatcher
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:203]: db_redis_print_all_tables():     schema:
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       description: 3
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       attrs: 3
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       flags: 0
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       destination: 3
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       priority: 0
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       setid: 0
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:208]: db_redis_print_all_tables():       id: 0
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:214]: db_redis_print_all_tables():     entry keys:
Nov 25 18:16:09 test COPS[18195]: DEBUG: db_redis [redis_table.c:217]: db_redis_print_all_tables():       id

Every time you do a dispatcher reload you get the warning. Debug logs:

Nov 25 18:01:13 test COPS[17825]: DEBUG: db_redis [redis_dbase.c:1761]: db_redis_query(): querying prefix (table) 'dispatcher'
Nov 25 18:01:13 test COPS[17825]: DEBUG: db_redis [redis_dbase.c:1811]: db_redis_query(): no columns given to build query keys, falling back to full table scan
Nov 25 18:01:13 test COPS[17825]: DEBUG: <core> [db_res.c:119]: db_new_result(): allocate 56 bytes for result set at 0x7efe768040b0
Nov 25 18:01:13 test COPS[17825]: DEBUG: <core> [db_res.c:156]: db_allocate_columns(): allocate 40 bytes for result names at 0x7efe76804150
Nov 25 18:01:13 test COPS[17825]: DEBUG: <core> [db_res.c:167]: db_allocate_columns(): allocate 20 bytes for result types at 0x7efe768041e0
Nov 25 18:01:13 test COPS[17825]: WARNING: db_redis [redis_dbase.c:1098]: db_redis_perform_query(): performing full table scan on table 'dispatcher' while performing query

Possible Solutions

I don't know the code, but I would think of:
a) fix what is causing the key to no be correctly set
or
b) exclude this warning from dispatcher table reload if it's not necessary

Additional Information

• Kamailio Version - output of kamailio -v

version: kamailio 5.4.0-dev2 (x86_64/linux)
flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES
ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: unknown
compiled with gcc 8.3.0

• Operating System:

Linux test 4.19.0-6-cloud-amd64 #1 SMP Debian 4.19.67-2+deb10u1 (2019-09-20) x86_64 GNU/Linux

[miconda]

I pushed a patch to not print the warning when it is supposed to load full table -- see the reference above. If still an issue, reopen.