Project

General

Profile

Watched Prefix Insertion Protocol » History » Version 19

Weiqi Shi, 08/01/2014 04:26 PM

1 1 Weiqi Shi
Watched Prefix Insertion Protocol
2
=================================
3
Watched Prefix is a new protocol for repo insertion. By using this protocol, repo keep sending interests to request the data with same prefix. When a data packet is received, repo will update selectors (exclude selector in most cases) to exclude the received data and request new one. Repo will stop watching the prefix until a command interest in tell it to stop, the total amount of sent interests reaches a specific number or time out.
4
5
## Basic operations
6
7 16 Weiqi Shi
### Start watched prefix insertion
8 1 Weiqi Shi
9 9 Weiqi Shi
Command verb: **watch start**
10 1 Weiqi Shi
11 12 Alex Afanasyev
The name semantics follows the format of the [[Repo Command]]. The <command verb> is defined as ``watch``.
12 1 Weiqi Shi
For example, for ``<repo prefix>`` as ``/ucla/cs/repo``, the following is an example:
13
14 9 Weiqi Shi
    /ucla/cs/repo/watch/start/<RepoCommandParameter>/<timestamp>/<random-value>/<SignatureInfo>/<SignatureValue>
15 1 Weiqi Shi
16 12 Alex Afanasyev
The command is using the following parameters:
17 1 Weiqi Shi
18 12 Alex Afanasyev
* ``Name`` (required)
19
* ``InterestLifetime`` (optional)
20
* ``MaxInterestNum`` (optional)
21
* ``WatchTimeout`` (optional)
22
* ``Selectors`` (optional)
23 1 Weiqi Shi
24 12 Alex Afanasyev
Detailed description of the parameters:
25 1 Weiqi Shi
26 12 Alex Afanasyev
* **`Name`** is the prefix that will be watched.
27 1 Weiqi Shi
28 12 Alex Afanasyev
* **`InterestLifetime`** is the maximum latency between interest sent and data received. If the time duration is larger than interest timeout, the same interest will be resent. If data is received within the Interest timeout, the selectors of the interest will be updated and sent to request new data. If it is not specified, a default value(4000 millisecond) will be set. 
29 1 Weiqi Shi
30 12 Alex Afanasyev
* **`MaxInterestNum`** is the maximum of total interests that can be sent. The process will stop if the total number of interests reaches this limit. If it is not specified, MaxInterestNum will be set as -1, means infinity.
31 1 Weiqi Shi
32 12 Alex Afanasyev
* **`WatchTimeout`** is the time duration of this process. Repo will keep watching the prefix until it times out. If it is not specified, WatchTimeout will be set as 0, means this process will run forever.
33 1 Weiqi Shi
34 12 Alex Afanasyev
* **`Selectors`** are used to exclude the received data and request new data.
35 1 Weiqi Shi
36 12 Alex Afanasyev
### Watch status check
37 1 Weiqi Shi
38 12 Alex Afanasyev
Command verb: **watch check**
39 1 Weiqi Shi
40 12 Alex Afanasyev
During the watched prefix progress, requester could send watch status check command to check the status of the progress. This status check command is also [[Repo Command]]. The semantics of watch status check command is shown as follows:
41 1 Weiqi Shi
42 12 Alex Afanasyev
    /ucla/cs/repo/watch/check/<RepoCommandParameter>/<timestamp>/<random-value>/<SignatureInfo>/<SignatureValue>
43 1 Weiqi Shi
44 12 Alex Afanasyev
The command is using the following parameters:
45 1 Weiqi Shi
46 18 Weiqi Shi
* ``Name`` (required)
47 1 Weiqi Shi
48 12 Alex Afanasyev
Detailed description of the parameters:
49 1 Weiqi Shi
50 18 Weiqi Shi
* **`Name`**  is the prefix which is being watched.
51 9 Weiqi Shi
52
53 12 Alex Afanasyev
### Stop watched prefix insertion
54 9 Weiqi Shi
55 12 Alex Afanasyev
Command verb: **watch stop**
56 9 Weiqi Shi
57 17 Weiqi Shi
During the watched prefix progress, requester could send watch stop command to stop the watched prefix insertion. The stop command is also a [[Repo Command]].
58 9 Weiqi Shi
59 12 Alex Afanasyev
    /ucla/cs/repo/watch/stop/<RepoCommandParameter>/<timestamp>/<random-value>/<SignatureInfo>/<SignatureValue>
60 14 Alex Afanasyev
61 1 Weiqi Shi
62 13 Alex Afanasyev
## RepoCommandResponse
63 1 Weiqi Shi
64
This watch status data object could be the response data object of both watch command and watchCheck command. It will follow the format of repo command response.
65
66 19 Weiqi Shi
Response has two part:InsertNumber, indicates how many data packets under the watched prefix has been inserted into repo; 
67 2 Weiqi Shi
StatusCode, indicates the status of the process.
68
69
StatusCode Definition:
70
71
``StatusCode`` | Description
72
-------------- | ----------------------------------------------
73
``100``        | The command is OK. Start to watch the prefix
74
``101``        | Watched Prefix Insertion is stop.
75
``300``        | This watched prefix Insertion is in progress
76
``401``        | This watch command or watchCheck command is invalidated
77
``402``        | BlockId present. BlockId is not supported in this protocol
78
``403``        | Malformed Command
79
``404``        | No such this process is in progress
80 3 Weiqi Shi
81
## Protocol Process
82
83 11 Weiqi Shi
### Repo watch start command process:
84 10 Weiqi Shi
85 3 Weiqi Shi
1. Start to validate the command. If it is validated, go to Step 3, otherwise go to Step 2.
86
87
2. Send a negative response indicating validation failure, and abort these steps, process ends (StatusCode: 401).
88
89
3. Check parameters. If it cannot be extracted from interest, send a negative response(StatusCode: 403) and stop process.
90
91
4. If it has BlockId, send a negative response(StatusCode: 402) and stop process.
92
93
5. Use parameter of the command interest to construct interest. Set the Rightmost Child Selector.
94
95
6. Send the interest and start timer. The number of sent interest plus 1(the initial value is 0).
96
97
7. If received a data, go to Step 8, if times out, go to Step 17.
98
99
8. If data is validated, go to Step 9, otherwise, go to Step 15.
100
101
9. Check whether the watched prefix insertion is still running. If it does not, process ends.
102
103
10. If the process times out(exceed watch timeout) or if total number of sent interest reaches limit, go to Step 11, otherwise go to Step 12.
104
105
11. Clear all the variables(the number of sent interest, watch timeout, interest lifetime), abort these steps, process ends.
106
107
12. Store the data into repo.
108
109
13. Update selectors, exclude from min to the received one and use the updated selectors construct new interest. 
110
111
14. Send new interest and the number of sent interest plus 1, and then go to Step 7.
112
113
15. Repeat Step 9 to 11 and skip Step 12.
114
115
16. Update selectors, only exclude the received data(since other data whose name is smaller may be satisfied), then go to Step 14.
116
117
17. Repeat Step 9 to 11 and skip Step 12.
118
119 4 Weiqi Shi
18. Send the interest again and the number of sent interest plus 1, and then go to Step 7.
120 1 Weiqi Shi
121 11 Weiqi Shi
### Repo watch check command process:
122 4 Weiqi Shi
123
1. Start to validate the check command. If it is validated, go to Step 3, otherwise, go to Step 2.
124
125
2. Send a negative response indicating validation failure, and abort these steps, process ends (StatusCode: 401).
126
127 19 Weiqi Shi
3. Check parameter. If it cannot extracted from interest or if it does not have the name to be checked, send a negative reply(StatusCode: 403).
128 4 Weiqi Shi
129 19 Weiqi Shi
4. Check whether the process is existed. If it does, go to Step 5, otherwise, send a negative reply(StatusCode: 404).
130 4 Weiqi Shi
131 1 Weiqi Shi
5. Use the processId to find the response and send the response back.
132 10 Weiqi Shi
133 11 Weiqi Shi
### Repo watch stop command process:
134 10 Weiqi Shi
135
1. Start to validate the stop command. If it is validated, go to Step 3, otherwise, go to Step 2.
136
137
2. Send a negative response indicating validation failure, and abort these steps, process ends (StatusCode: 401).
138
139 19 Weiqi Shi
3. Check parameter. If it cannot extracted from interest, send a negative reply(StatusCode: 403).
140 10 Weiqi Shi
141 19 Weiqi Shi
4. Stop the process and send a negative reply (StatusCode: 101).