1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/*
* Copyright (c) 2016-Present, Redis Ltd.
* All rights reserved.
*
* Licensed under your choice of (a) the Redis Source Available License 2.0
* (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the
* GNU Affero General Public License v3 (AGPLv3).
*/
#include "server.h"
#include <unistd.h>
#include <fcntl.h>
typedef struct {
size_t keys;
size_t cow;
monotime cow_updated;
double progress;
childInfoType information_type; /* Type of information */
} child_info_data;
/* Open a child-parent channel used in order to move information about the
* RDB / AOF saving process from the child to the parent (for instance
* the amount of copy on write memory used) */
void openChildInfoPipe(void) {
if (anetPipe(server.child_info_pipe, O_NONBLOCK, 0) == -1) {
/* On error our two file descriptors should be still set to -1,
* but we call anyway closeChildInfoPipe() since can't hurt. */
closeChildInfoPipe();
} else {
server.child_info_nread = 0;
}
}
/* Close the pipes opened with openChildInfoPipe(). */
void closeChildInfoPipe(void) {
if (server.child_info_pipe[0] != -1 ||
server.child_info_pipe[1] != -1)
{
close(server.child_info_pipe[0]);
close(server.child_info_pipe[1]);
server.child_info_pipe[0] = -1;
server.child_info_pipe[1] = -1;
server.child_info_nread = 0;
}
}
/* Send save data to parent. */
void sendChildInfoGeneric(childInfoType info_type, size_t keys, double progress, char *pname) {
if (server.child_info_pipe[1] == -1) return;
static monotime cow_updated = 0;
static uint64_t cow_update_cost = 0;
static size_t cow = 0;
static size_t peak_cow = 0;
static size_t update_count = 0;
static unsigned long long sum_cow = 0;
child_info_data data = {0}; /* zero everything, including padding to satisfy valgrind */
/* When called to report current info, we need to throttle down CoW updates as they
* can be very expensive. To do that, we measure the time it takes to get a reading
* and schedule the next reading to happen not before time*CHILD_COW_COST_FACTOR
* passes. */
monotime now = getMonotonicUs();
if (info_type != CHILD_INFO_TYPE_CURRENT_INFO ||
!cow_updated ||
now - cow_updated > cow_update_cost * CHILD_COW_DUTY_CYCLE)
{
cow = zmalloc_get_private_dirty(-1);
cow_updated = getMonotonicUs();
cow_update_cost = cow_updated - now;
if (cow > peak_cow) peak_cow = cow;
sum_cow += cow;
update_count++;
int cow_info = (info_type != CHILD_INFO_TYPE_CURRENT_INFO);
if (cow || cow_info) {
serverLog(cow_info ? LL_NOTICE : LL_VERBOSE,
"Fork CoW for %s: current %zu MB, peak %zu MB, average %llu MB",
pname, cow>>20, peak_cow>>20, (sum_cow/update_count)>>20);
}
}
data.information_type = info_type;
data.keys = keys;
data.cow = cow;
data.cow_updated = cow_updated;
data.progress = progress;
ssize_t wlen = sizeof(data);
if (write(server.child_info_pipe[1], &data, wlen) != wlen) {
/* Failed writing to parent, it could have been killed, exit. */
serverLog(LL_WARNING,"Child failed reporting info to parent, exiting. %s", strerror(errno));
exitFromChild(1, 0);
}
}
/* Update Child info. */
void updateChildInfo(childInfoType information_type, size_t cow, monotime cow_updated, size_t keys, double progress) {
if (cow > server.stat_current_cow_peak) server.stat_current_cow_peak = cow;
if (information_type == CHILD_INFO_TYPE_CURRENT_INFO) {
server.stat_current_cow_bytes = cow;
server.stat_current_cow_updated = cow_updated;
server.stat_current_save_keys_processed = keys;
if (progress != -1) server.stat_module_progress = progress;
} else if (information_type == CHILD_INFO_TYPE_AOF_COW_SIZE) {
server.stat_aof_cow_bytes = server.stat_current_cow_peak;
} else if (information_type == CHILD_INFO_TYPE_RDB_COW_SIZE) {
server.stat_rdb_cow_bytes = server.stat_current_cow_peak;
} else if (information_type == CHILD_INFO_TYPE_MODULE_COW_SIZE) {
server.stat_module_cow_bytes = server.stat_current_cow_peak;
}
}
/* Read child info data from the pipe.
* if complete data read into the buffer,
* data is stored into *buffer, and returns 1.
* otherwise, the partial data is left in the buffer, waiting for the next read, and returns 0. */
int readChildInfo(childInfoType *information_type, size_t *cow, monotime *cow_updated, size_t *keys, double* progress) {
/* We are using here a static buffer in combination with the server.child_info_nread to handle short reads */
static child_info_data buffer;
ssize_t wlen = sizeof(buffer);
/* Do not overlap */
if (server.child_info_nread == wlen) server.child_info_nread = 0;
int nread = read(server.child_info_pipe[0], (char *)&buffer + server.child_info_nread, wlen - server.child_info_nread);
if (nread > 0) {
server.child_info_nread += nread;
}
/* We have complete child info */
if (server.child_info_nread == wlen) {
*information_type = buffer.information_type;
*cow = buffer.cow;
*cow_updated = buffer.cow_updated;
*keys = buffer.keys;
*progress = buffer.progress;
return 1;
} else {
return 0;
}
}
/* Receive info data from child. */
void receiveChildInfo(void) {
if (server.child_info_pipe[0] == -1) return;
size_t cow;
monotime cow_updated;
size_t keys;
double progress;
childInfoType information_type;
/* Drain the pipe and update child info so that we get the final message. */
while (readChildInfo(&information_type, &cow, &cow_updated, &keys, &progress)) {
updateChildInfo(information_type, cow, cow_updated, keys, progress);
}
}
|
