Dump SOW File
amps_sow_dump is a utility used to inspect the contents of a SOW topic store. Additionally, it can be used to gather summary statistics on a SOW file.
Options and Parameters
Option
Description
filename
(required)
Filename of the SOW file.
-n LIMIT
Maximum number of records to print per file.
-v, --verbose
Print record metadata for records and file summary.
--sizing-chart
Print memory sizing chart for efficiency comparison (experimental).
-e, --escape
Escape special characters in record data and header.
-d DELIMITER
Prints only the record data using the provided ASCII character value as the record delimiter [default: 10 for newline].
--version
Show the version number of the program and exit.
-h, --help
Show the help message and exit.
Usage
The following listing shows a simple sow dump of a fix format topic with the -e flag set to make the header, message and field separators readable. Each key which exists in the order.sow file is dumped out to stdout. This output can easily be redirected to a new file, or piped into another program for further analysis.
This example also uses the -e flag which escapes the special characters. The purpose of this is to simplify the output presented. The field separator used in this example is byte 1 which is replaced with as \x01 by the -e flag.. If this flag was not used, then a non-ascii character would be displayed, making the output harder to read.
%> ./amps_sow_dump -e ./order.sow
id=0\x01value=1743\x01
id=1\x01value=6554\x01
id=2\x01value=3243\x01
id=3\x01value=5332\x01
id=4\x01value=3725\x01
id=5\x01value=1598\x01
id=6\x01value=6094\x01
id=7\x01value=7524\x01
id=8\x01value=2432\x01
id=9\x01value=9669\x01
id=10\x01value=140\x01Verbose Output
The amps_sow_dump utility also provides for verbose output, which will display more information about the file and its structure in addition to the records contained in the file.
# This is the last record reported by amps_sow_dump for this sample SOW file.
key = 13480918659780819530
crc = 3156974437
flags = 0
file offset = 4352
slab offset = 4096
allocated = 128
data size = 21
expiration = 0
update = 0
generation = 0
seq = 0
data = [1=10001
2=aaaaaaaaaa
]
File : ./sow/order.sow
Version : amps-sow-v1.0
Valid Keys : 10000
Record Size : 512
Maximum Records : 10000
Multirecords : 0
Maximum record size : 21
Average record size : 21.00
Slab Count : 1
Slab Detail
size : 5128192
file offset : 4096
valid count : 10000
invalid count : 0
stored bytes : 1280000
data bytes : 210000
deleted bytes : 0Sizing Chart
The example below shows the output from the --sizing-chart flag. This is feature can be useful in tuning AMPS memory usage and performance. The Record Size with the asterisk shows the current Record Size setting and allows an AMPS administrator to compare memory usage efficiency along with the potential for a multi-record penalty.
This feature is currently considered to be experimental, so changing AMPS record size configuration based on the results may not necessarily help performance, and could hurt performance in some cases.
%> ./amps_sow_dump --sizing-chart ./order.sow
=============================================================
Record Size Store Efficiency Multirecords
=============================================================
128 128 B 100.00% 0
256 256 B 50.00% 0
384 384 B 33.33% 0
512* 512 B 25.00% 0
640 640 B 20.00% 0
768 768 B 16.67% 0
896 896 B 14.29% 0
1024 1024 B 12.50% 0
1152 1.12 KB 11.11% 0
1280 1.25 KB 10.00% 0
1408 1.38 KB 9.09% 0
1536 1.50 KB 8.33% 0
1664 1.62 KB 7.69% 0
1792 1.75 KB 7.14% 0
1920 1.88 KB 6.67% 0Last updated