Swap space getting used

I am having a system with 8GB of RAM and running mysql on it ,top command shows

Mem: 8124416k total, 8110004k used, 14412k free, 21292k buffers
Swap: 8388600k total, 1712132k used, 6676468k free, 2058600k cached

vmstat 1 gives this output

 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 3  0 1712132  38596  21628 2033920    0    0   451    77    0    1 14  1 81  5  0
 1  0 1712132  38412  21628 2033928    0    0    32     0  695  534  9  1 90  1  0
 0  0 1712132  37992  21656 2034412    0    0   476   136  630  474  8  0 84  8  0
 0  0 1712132  37992  21656 2034424    0    0     0     0  232  138  4  0 96  0  0
 2  0 1712132  37540  21656 2034424    0    0     0     0  463  228 41  1 58  0  0
 1  0 1712132  37480  21656 2034440    0    0    16     0  393  208 26  0 74  0  0

 2  0 1712132  37932  21664 2034432    0    0     0   244  655  454 38  1 59  2  0
 1  0 1712132  38056  21664 2034440    0    0     0     0  403  193 36  0 63  0  0
 0  0 1712132  38056  21664 2034440    0    0    16    16  498  362 13  0 87  0  0
 3  0 1712132  37872  21664 2034488    0    0    48     0  463  350  9  1 89  1  0
 1  0 1712132  37996  21664 2034488    0    0    16     0  765  536 29  0 70  0  0
 3  0 1712132  37996  21672 2034512    0    0    16    92  855  539 46  1 53  0  0
 2  0 1712132  38432  21676 2034508    0    0    20     0 1015  545 63  1 36  0  0
 0  0 1712132  38680  21684 2034544    0    0     0    72  540  307 34  0 66  0  0
 6  0 1712132  38556  21684 2034544    0    0     0     0  926  518 80  1 20  0  

0

free -m gives

             total       used       free     shared    buffers     cached
Mem:          7934       7910         23          0         21       1999
-/+ buffers/cache:       5889       2044
Swap:         8191       1672       6519

is the use of swap space a concern or is it normal and ok.

Thanks IN advance
Pankaj

Answer

The important column in your case isn't swpd but si and so. It's normal and healthy for Linux to swap unused stuff out. If, however, si and so showed constant activity, that would imply that you did not have adequate resources for your usage pattern. As others have pointed out, that would mean you had either a leaky app or just not enough RAM.

Frankly, I don't see anything disconcerting about the vmstat info you've posted.