MySQL Server has gone away issue

Your software
My Mautic version is: 2.15.3
My PHP version is: PHP Version 7.2.24-1+ubuntu18.04.1+deb.sury.org+1

Your problem
Ive got this problem first time, never had it before and now it happens… I have set the following in mysql

max_allowed_packet = 100M
innodb_log_file_size = 128M
wait_timeout = 28800

I am trying to send emails to about 300k people and seems the size of the set is the problem

The error occurs as such

 [Doctrine\DBAL\Exception\DriverException]
An exception occurred while executing ‘SELECT ch.lead_id, IFNULL(fr.frequency_number,?) as frequency_number, IFNULL(fr.frequency_time,?) as frequency_time FROM pb_email_stats ch LEFT JOIN pb_lead_freque
ncyrules fr ON ch.lead_id = fr.lead_id WHERE (fr.channel = ? or fr.channel is null) AND (ch.date_sent >= case fr.frequency_time
when ‘MONTH’ then DATE_SUB(NOW(),INTERVAL 1 MONTH)
when ‘DAY’ then DATE_SUB(NOW(),INTERVAL 1 DAY)
when ‘WEEK’ then DATE_SUB(NOW(),INTERVAL 1 WEEK)
else DATE_SUB(NOW(),INTERVAL 1 WEEK)
end) AND (ch.lead_id IN (481342, 481354, 481356, 481365, 481386, 481390, 481412, 481429, 481448, 481457, 481459, 481461, 481467, 481468, 481471, 481478, 481480, 481482, 481486, 48149
1, 481495, 481499, 481500, 481501, 481502, 481512, 481513, 481530, 481535, 481536, 481547, 481551, 481553, 481556, 481560, 481561, 481583, 481585, 481593, 481601, 481613, 481615, 481631, 481634, 481640,
481646, 481662, 481664, 481665, 481678, 481680, 481695, 481696, 481701, 481705, 481709, 481714, 481723, 481735, 481737, 481748, 481753, 481773, 481776, 481788, 481790, 481792, 481806, 481809, 481817, 4
81818, 481823, 481837, 481843, 481844, 481857, 481864, 481865, 481872, 481876, 481890, 481898, 481908, 481922, 481924, 481935, 481937, 481941, 481944, 481950, 481951, 481961, 481968, 481982, 481983, 481
988, 481993, 481997, 482006, 482010, 482013, 482023, 482036, 482041, 482044, 482045, 482051, 482102, 482104, 482117, 482120, 482125, 482126, 482127, 482132, 482143, 482147, 482153, 482154, 482165, 48216
7, 482184, 482192, 482204, 482209, 482211, 482217, 482220, 482222, 482230, 482240, 482246, 482251, 482255, 482257, 482259, 482262, 482268, 482275, 482279, 482288, 482302, 482313, 482323, 482324, 482327,
482334, 482344, 482350, 482357, 482365, 482407, 482414, 482415, 482423, 482426, 482436, 482439, 482454, 482464, 482475, 482484, 482488, 482496, 482500, 482506, 482509, 482511, 482515, 482516, 482518, 4
82531, 482532, 482533, 482534, 482540, 482545, 482546, 482568, 482569, 482571, 482572, 482577, 482579, 482583, 482584, 482589, 482591, 482599, 482600, 482604, 482617, 482623, 482626, 482627, 482639, 482
640, 482647, 482653, 482657, 482665, 482679, 482686, 482689, 482691, 482700, 482708, 482710, 482711, 482723, 482741, 482745, 482752, 482753, 482754, 482757, 482762, 482763, 482765, 482767, 482773, 48278
0, 482791, 482798, 482803, 482806, 482816, 482825, 482833, 482844, 482850, 482852, 482869, 482877, 482886, 482890, 482896, 482901, 482908, 482910, 482920, 482927, 482930, 482937, 482938, 482944, 482949,
482959, 482964, 482978, 482986, 482989, 482990, 482991, 482993, 482994, 482996, 483004, 483008, 483015, 483024, 483033, 483043, 483052, 483053, 483059, 483062, 483068, 483069, 483071, 483078, 483089, 4
83097, 483100, 483114, 483118, 483124, 483125, 483129, 483145, 483158, 483165, 483168, 483174, 483181, 483190, 483216, 483233, 483240, 483242, 483249, 483257, 483260, 483264, 483266, 483273, 483279, 483
289, 483293, 483306)) GROUP BY ch.lead_id, fr.frequency_time, fr.frequency_number HAVING (count(ch.lead_id) >= IFNULL(fr.frequency_number,?) AND ch.lead_id IN (481342, 481354, 481356, 481365, 481386, 48
1390, 481412, 481429, 481448, 481457, 481459, 481461, 481467, 481468, 481471, 481478, 481480, 481482, 481486, 481491, 481495, 481499, 481500, 481501, 481502, 481512, 481513, 481530, 481535, 481536, 4815
47, 481551, 481553, 481556, 481560, 481561, 481583, 481585, 481593, 481601, 481613, 481615, 481631, 481634, 481640, 481646, 481662, 481664, 481665, 481678, 481680, 481695, 481696, 481701, 481705, 481709
, 481714, 481723, 481735, 481737, 481748, 481753, 481773, 481776, 481788, 481790, 481792, 481806, 481809, 481817, 481818, 481823, 481837, 481843, 481844, 481857, 481864, 481865, 481872, 481876, 481890,
481898, 481908, 481922, 481924, 481935, 481937, 481941, 481944, 481950, 481951, 481961, 481968, 481982, 481983, 481988, 481993, 481997, 482006, 482010, 482013, 482023, 482036, 482041, 482044, 482045, 48
2051, 482102, 482104, 482117, 482120, 482125, 482126, 482127, 482132, 482143, 482147, 482153, 482154, 482165, 482167, 482184, 482192, 482204, 482209, 482211, 482217, 482220, 482222, 482230, 482240, 4822
46, 482251, 482255, 482257, 482259, 482262, 482268, 482275, 482279, 482288, 482302, 482313, 482323, 482324, 482327, 482334, 482344, 482350, 482357, 482365, 482407, 482414, 482415, 482423, 482426, 482436
, 482439, 482454, 482464, 482475, 482484, 482488, 482496, 482500, 482506, 482509, 482511, 482515, 482516, 482518, 482531, 482532, 482533, 482534, 482540, 482545, 482546, 482568, 482569, 482571, 482572,
482577, 482579, 482583, 482584, 482589, 482591, 482599, 482600, 482604, 482617, 482623, 482626, 482627, 482639, 482640, 482647, 482653, 482657, 482665, 482679, 482686, 482689, 482691, 482700, 482708, 48
2710, 482711, 482723, 482741, 482745, 482752, 482753, 482754, 482757, 482762, 482763, 482765, 482767, 482773, 482780, 482791, 482798, 482803, 482806, 482816, 482825, 482833, 482844, 482850, 482852, 4828
69, 482877, 482886, 482890, 482896, 482901, 482908, 482910, 482920, 482927, 482930, 482937, 482938, 482944, 482949, 482959, 482964, 482978, 482986, 482989, 482990, 482991, 482993, 482994, 482996, 483004
, 483008, 483015, 483024, 483033, 483043, 483052, 483053, 483059, 483062, 483068, 483069, 483071, 483078, 483089, 483097, 483100, 483114, 483118, 483124, 483125, 483129, 483145, 483158, 483165, 483168,
483174, 483181, 483190, 483216, 483233, 483240, 483242, 483249, 483257, 483260, 483264, 483266, 483273, 483279, 483289, 483293, 483306))’ with params [“3”, “WEEK”, “email”, “3”]:

SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

I just solved the problem by including the limit in the scheduled task

mautic:emails:send --limit=50000
mautic:broadcasts:send --limit=50000

try to see if it works for you