1Perlbal::Manual::DebuggUisnegr(3C)ontributed Perl DocumePnetraltbiaoln::Manual::Debugging(3)
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NAME

6       Perlbal::Manual::Debugging - Debugging Perlbal
7
8   VERSION
9       Perlbal 1.78.
10
11   DESCRIPTION
12       Perlbal has two ways of debugging.
13
14       One of them is through a management console; the other is through
15       debugging messages.
16
17   Debugging in a console
18       You'll need to set up a management service and use it to dump all the
19       information you require.
20
21       The comprehensive documentation on this process can be found at
22       Perlbal::Manual::Management.
23
24   Debugging messages
25       You can control the ammount of debugging messages Perlbal dumps by
26       setting the environment variable "PERLBAL_DEBUG" to a value between 0
27       and 4:
28
29           PERLBAL_DEBUG = 0 # no debug
30
31           PERLBAL_DEBUG = 4 # debug everything
32
33       Debug level 1
34
35       You can activate basic debug by setting "PERLBAL_DEBUG" to 1:
36
37           PERLBAL_DEBUG = 1
38
39       The following debugging messages are turned on:
40
41       •   When a connection to a backend is closed, Perlbal::BackendHTTP
42           prints "Backend $self is done; closing..."
43
44       •   When a connection to a backend is killed, Perlbal::ClientProxy
45           prints "Client ($self) closing backend ($backend)"
46
47       •   When an HTTP request fails to be parsed, Perlbal::HTTPHeaders
48           prints "HTTP parse failure: $reason"
49
50       •   When the connection is promoted to SSL, Perlbal::TCPListener prints
51           "  .. socket upgraded to SSL!"
52
53       Debug level 2
54
55       By setting the debug level to 2 you'll get all the messages from level
56       1.
57
58           PERLBAL_DEBUG = 2
59
60       You will also get a few others:
61
62       •   When a connection to a backend is opened and ready to be written
63           to, Perlbal::BackendHTTP prints "Backend $self is writeable!"
64
65       •   When a response is about to be handled, Perlbal::BackendHTTP prints
66           "BackendHTTP: handle_response"
67
68       •   When a backend is ready to be read from, Perlbal::BackendHTTP
69           prints "Backend $self is readable!"
70
71       •   When there's an error with the connection to the backend,
72           Perlbal::BackendHTTP prints "BACKEND event_err"
73
74       •   Whenever we're determining if we should be sending keep-alive
75           header information back to the client, Perlbal::ClientHTTPBase
76           prints ClientHTTPBase::setup_keepalive($self)
77
78       •   Whenever the client is ready for more of its file,
79           Perlbal::ClientHTTPBase prints "REPROXY SSL done"
80
81       •   Right after we've read a chunk of a file and when a reproxy request
82           is about to be sent, Perlbal::ClientHTTPBase prints "REPROXY Sent:
83           $sent"
84
85       •   When we've written all data in the queue (and are about to stop
86           waiting for write notifications), Perlbal::ClientHTTPBase prints
87           "All writing done to $self"
88
89       •   Whenever a client proxy is about to be closed, Perlbal::ClientProxy
90           prints "Perlbal::ClientProxy closed", followed by a possible
91           "again" and a possible "saying $reason"
92
93       •   When a client has disconnected, Perlbal::ClientProxy prints
94           "ClientProxy::client_disconnected"
95
96       •   When a backend requests a client of a high priority request and the
97           client is available, "Service" in Perlbal prints "Got from fast
98           queue, in front of $backlog others"
99
100       •   When a backend requests a client of a normal priority request and
101           the client is available, "Service" in Perlbal prints "Backend
102           requesting client, got PRIORITY = $cp-"{fd}.>
103
104       •   When a backend requests a client of a low priority request and the
105           client is available, "Service" in Perlbal prints "Backend
106           requesting client, got low priority = $cp-"{fd}.>
107
108       •   When header are being read, Perlbal::Socket prints
109           "Perlbal::Socket::read_headers($self) is_res=$is_res"
110
111       Debug level 3
112
113           PERLBAL_DEBUG = 3
114
115       By setting the debug level to 3 you'll get all the messages from level
116       1 and 2 plus the following:
117
118       •   Right before response headers are written to the client,
119           Perlbal::BackendHTTP prints "  writing response headers to client"
120
121       •   As we're writing to the client, Perlbal::BackendHTTP prints "
122           content_length=VALUE" and "  remain=VALUE", where the values are
123           "undef" if they are not defined
124
125       •   If we're done writing to the client, Perlbal::BackendHTTP prints "
126           done.  detaching."
127
128       •   Whenever we're determining if we should be sending keep-alive
129           header information back to the client, Perlbal::ClientHTTPBase
130           prints "  service's persist_client = $persist_client"
131
132       •   While determining if we should be sending keep-alive header
133           information back to the client, if we were sent "content-length" or
134           it's a head request, as we're doing a keep alive
135           Perlbal::ClientHTTPBase prints "  doing keep-alive to client"
136
137       •   If we're not sending keep-alive header information back ot the
138           client, Perlbal::ClientHTTPBase prints "  doing connection: close"
139
140       •   Right after we've finished sending all of the results to the user,
141           Perlbal::ClientProxy prints "ClientProxy::backend_finished"
142
143       •   When we've sent a response to a user fully and we need to reset
144           state, Perlbal::ClientProxy prints "ClientProxy::http_response_sent
145           -- resetting state"
146
147       •   When we're writing a response to a client, Perlbal::ClientProxy
148           prints "ClientProxy::event_write"
149
150       •   After writing a response to a client, if it is still connected and
151           we're triggering trigger our backend to keep reading,
152           Perlbal::ClientProxy prints "  unstalling backend"
153
154       •   When reading a request, Perlbal::ClientProxy prints
155           "ClientProxy::event_read"
156
157       •   When reading a request and just before we read the headers,
158           Perlbal::ClientProxy prints "  no headers.  reading."
159
160       •   When reading a request, if we're not buffering to disk or we're no
161           longer reading, as we disable reads, Perlbal::ClientProxy prints "
162           disabling reads."
163
164       •   As we're reading, Perlbal::ClientProxy prints "  reading $read_size
165           bytes (VALUE bytes remain)", where "VALUE bytes remain" can be
166           <undef>
167
168       •   After each read, Perlbal::ClientProxy prints "  read $len bytes"
169
170       •   After we finished reading the request, Perlbal::ClientProxy prints
171           "  done_reading = $done_reading, backend = BACKEND", where
172           "BACKEND" can be "undef"
173
174       •   When we send the headers to the backend and it responds before
175           we're done reading from the client, further reads from the client
176           are discarded; in this situation Perlbal::ClientProxy prints "
177           already responded.". If the client continues to send data,
178           Perlbal::ClientProxy prints "  already responded [2]." and then
179           gives up on reading
180
181       •   After reading, and having a backend available where we can write
182           to, just before we do, Perlbal::ClientProxy prints "  got a
183           backend.  sending write to it."
184
185       •   After reading, if there's no backend available,
186           Perlbal::ClientProxy prints "  no backend.  read_ahead =
187           $self-"{read_ahead}.>
188
189       •   If we know we've already started spooling a file to disk and we're
190           about to continue doing so, Perlbal::ClientProxy prints "  bureason
191           = $self-"{bureason}>
192
193       •   If a backend wasn't available and we're about to request one,
194           Perlbal::ClientProxy prints "  finally requesting a backend"
195
196       •   When we're trying to read headers and the client has disconnected,
197           Perlbal::Socket prints "  client disconnected"
198
199       •   If we need to remove a trailing "\r\n" from the headers,
200           Perlbal::Socket prints "  throwing away leading \r\n"
201
202       •   If we've read a packet with headers and by the end of it we can't
203           find the end of them, Perlbal::Socket prints "  can't find end of
204           headers"
205
206       •   Once we've read some headers, Perlbal::Socket prints "  pre-parsed
207           headers: [$hstr]"
208
209       •   After reading headers, if there's additional content that we've
210           read, we push it back; when we do so, Perlbal::Socket prints "
211           pushing back $len bytes after header"
212
213       •   If we got bogus headers, and right before we close the connection
214           due to a parsing failure, Perlbal::Socket prints "  bogus headers"
215
216       •   If we got valid headers, Perlbal::Socket prints "  got valid
217           headers"
218
219       •   If we're reading buffered data from a client, Perlbal::Socket
220           prints "draining readbuf from $self to $dest: [$$bref]"
221
222       Debug level 4
223
224       By setting the debug level to 4 you get all the messages from levels 1
225       to 3.
226
227       Plus, "write" is redefined so that whenever "write" is called it first
228       prints "write($self, <$clen>"$content") from ($pkg, $filename, $line)".
229
230           PERLBAL_DEBUG = 4
231
232   SEE ALSO
233       Perlbal::Manual::Configuration, Perlbal::Manual::Management.
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237perl v5.36.0                      2023-01-18     Perlbal::Manual::Debugging(3)