stats: fix prometheus exporter crash on large number of FIB entries

Type: fix

Currently, prometheus exporter may crash because of memory exhaustion
when dumps metrics if the FIB contains large number of routes.

With this fix, increase memory size for prometheus exporter to be able
to handle large number of FIB entries.

Signed-off-by: Alexander Chernavin <achernavin@netgate.com>
Change-Id: Ia2b9a665368883c87448deee9bcf8d2ac1168357

src/vpp/app/vpp_prometheus_export.c

@@ -244,8 +244,8 @@ main (int argc, char **argv)
   u8 *stat_segment_name, *pattern = 0, **patterns = 0;
   int rv;
 
-  /* Allocating 32MB heap */
-  clib_mem_init (0, 32 << 20);
+  /* Allocating 256MB heap */
+  clib_mem_init (0, 256 << 20);
 
   unformat_init_command_line (a, argv);