Lt. Col. Oliver North on the Frontline of Israel’s Fight for Freedom

Watch Lt. Col. Oliver North explain why the people of Israel have absolutely no intention of ever being driven from their homeland again on this episode of the NRA TV series Frontline.


The post Lt. Col. Oliver North on the Frontline of Israel’s Fight for Freedom appeared first on Bearing Arms.

via Bearing Arms
Lt. Col. Oliver North on the Frontline of Israel’s Fight for Freedom

3-2-1 backup system will help you keep your digital images forever

3-2-1 backup system will help you keep your digital images forever

No matter if you are a professional photographer or a hobbyist, I’m sure your photos are important to you. Therefore, it’s essential to have a good backup system so you can avoid any situation that may result in losing them all. David Bergman suggests an effective 3-2-1 backup system. It will protect your images from any situation that may hinder them, and save you from losing years of work.

Losing digital files can come as a result of different circumstances, such as theft, natural disaster or data corruption. This is why you need to have all these situations in mind and create a 3-2-1 backup system: it includes 3 copies, 2 separate devices and 1 offsite backup.

3 copies – this means you need to have the original file and two separate backups.

2 devices – creating your two copies on a single device or the same hard disk simply don’t work. Imagine a situation where you have two copies on the same hard drive, and that drive dies. You can say goodbye to all the files. So, use two completely separate devices. If one dies, you can plug in the other and keep working like nothing happened. With hard drives it’s not the question if they’ll break, but when.

1 offsite backup – even if you have a backup on two separate devices, there are situation when this may not be enough. What if it comes to a theft, a fire or a flood? This is why you need to have one backup at a totally different place. David used to send the third hard copy to his mom’s place out of the state. But today, we have plenty of cloud options. You’ll agree this is much more convenient. You can set the cloud to automatic backup and always stay covered.

If you apply this backup strategy, I assume you can hardly be left without your photos, and it you can apply it to other files, too.

[3-2-1 Back Up : Two Minute Tips with David Bergman | Adorama TV]

via DIYPhotography.net – Photography and Studio Lighting – Do It Yourself
3-2-1 backup system will help you keep your digital images forever

HandBrake 1.0.0 Released After 13 Years Of Development

HandBrake, popular open source video transcoder, has finally hit version 1.0.0 affter spending roughly more than 13 years in development. HandBrake 1.0.0 brings tons of new presets and support for more devices and file types. From a report: HandBrake 1.0.0 comes with new web and MKV presets. The official presets from HandBrake 0.10.x can be found under ‘Legacy.’ New Jason-based preset system, including command line support, has been added. The additional features of HandBrake are title/chapter selection, queuing up multiple encodes, chapter markers, subtitles, different video filters, and video preview. Just in case you have a compatible Skylake or later CPU, Intel QuickSync Video H.265/HEVC encoder support brings performance improvements. HandBrake 1.0.0 also brings along new online documentation beta. It’s written in a simple and easy-to-understand language.You can download it here.



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Read more of this story at Slashdot.

via Slashdot
HandBrake 1.0.0 Released After 13 Years Of Development

Rogue One’s Missing Trailer Scenes

Rogue One’s Missing Trailer Scenes

Link

(SPOILERS) Rogue One: A Star Wars Story turned out to be a great film. But if you watched its trailers, you’ll know that there are some scenes that did not make it to the final movie. Looper lists those scenes and give a possible reason as to why they were cut.

via The Awesomer
Rogue One’s Missing Trailer Scenes

Kylo Ren Reviews Rogue One (SPOILERS)

Kylo Ren Reviews Rogue One (SPOILERS)

“Do not bring your HR complaints to a Dark Lord of the Sith.” YouTube channel Auralnauts hit comedy gold when they parodied Kylo Ren and made him react to the trailers of Rogue One: A Star Wars Story. They recently delivered the obvious conclusion to this gag.

In his review, Kylo rants about missing scenes, Magic Stick Man and Admiral Aimbot. He also impersonates Saw Gerrera (i.e. it’s a dude impersonating a dude impersonating a dude), but the Sith zealot comes alive when he heaps praises upon his idol and grandfather.

via MightyMega
Kylo Ren Reviews Rogue One (SPOILERS)

Year in Review: OSU salaries, who qualifies for medical marijuana, Limited layoffs, Bob Evans closings and other tops stories of 2016

Yesterday we ranked our 10 most-popular online posts of the year, a list that was made up of slideshows, including a photo tour of the historic Huntington House that’s for sale in Bexley.
Our most-viewed stories of the year – with no slideshows – involve everything from Ohio State salaries to the Smart City Challenge win to the reveal of our annual Forty Under 40 class.
Here are the stories that drew the most reader interest in 2016.
OSU salary database Here are the conditions that qualify…

via Columbus Business News – Local Columbus News | Business First of Columbus
Year in Review: OSU salaries, who qualifies for medical marijuana, Limited layoffs, Bob Evans closings and other tops stories of 2016

Back Up Your Data With Rsync (No Desktop Required)

Rsync is fairly simple: it’s a tool that’s specialized in copying files. For us, this means that rsync removes many inconveniences involved in manual backups. This results in a more seamless backup process, compared to using the file manipulation commands native to the Linux terminal


How to Manage Files in the Linux Terminal and Desktop




How to Manage Files in the Linux Terminal and Desktop

Once you make the change to Linux, you’ll find a sensible desktop that is easy to use, from installing new apps and launching them to organizing your data.
Read More

.

For example, rsync recognizes unchanged files from the last transfer, and saves time by not overwriting them. Other things like the ability to compress your files also make your backups more speed efficient. While these sorts of things could be theoretically done by hand, rsync puts all of these tasks into one convenient tool


10 Easy Ways to Restore Your Linux System




10 Easy Ways to Restore Your Linux System

Windows’ System Restore feature is a good way of making and maintaining entire system backups. If only Linux had a similar feature… oh wait, it does – in fact, we’ve got 10 options to choose…
Read More

.

We’ve already covered Grsync


Grsync – A Simple GUI to Help You Use ‘rsync’ Easily [Linux]




Grsync – A Simple GUI to Help You Use ‘rsync’ Easily [Linux]


Read More

in the past, but knowing how to use the tool powering it (that is, rsync) can prove to be a valuable asset. Hopefully, this article will demonstrate to you that using rsync without a graphical back-end is a fairly simple task.

Rsync Basics

All rsync commands are fundamentally the same, so it should be easy enough to pick up. Here’s the most basic command which simply copies the contents of one folder to another:

rsync -r -u -v ~/Source-Folder/ ~/Copy-Folder

rsync basic

The -r option stands for “recursive“. Put simply, without this option, rsync ignores files which are stored inside folders, meaning it won’t copy everything. We add the -u option (for “update“) to ensure that your transferred files won’t overwrite files in the target folder which are more up to date. For example, if you edited a file in the transfer folder, but didn’t from the original folder.

The -v option (for “verbose“) lets you see what rsync has done, which is good for monitoring its behaviour and actions. It’s not strictly necessary, but you might end up appreciating the extra information — without it, rsync is much more silent.

For more advanced forms of backup, all we have to do is to add extra options (i.e. -[letter]) to rsync. You can actually put all these letters together in one single, big option (e.g. -ruv) if you want to save space. Just remember to put them in before specifying your folders!

Choosing Your Backup Directories

As you saw above, you first select the folder which you’d like to copy files from, and then select where you’d like them copied to. Also take note of the trailing / at the end of the source folder. Doing this ensures that you’re only copying the contents of the folder, rather than the folder itself. You can leave out this forward-slash if you’d rather bring the folder along.

Helpful tip: the ~/ symbol represents your home folder


What Are Those Folders in Your Linux Root Directory?




What Are Those Folders in Your Linux Root Directory?

Open a file manager on your Linux box and select Computer in the sidebar to display your system folders. But do you have any idea what each of them hold? Let’s take a look!
Read More

(where your Documents, Desktop, Downloads, Music, etc. folders are stored). This is much faster than simply typing out your full source folder location, and is username agnostic.

Excluding Files and Folders With rsync

Sometimes, you don’t want to back up entire folders worth of data, and rsync can handle that as well. Apart from just choosing more specific folders to copy, you can also use the –exclude option to skip them. This lets you tell rsync to ignore a selected folder, file, or pattern.

rsync -ruv --exclude 'Subfolder' ~/Source-Folder/ ~/Copy-Folder

rsync folder exclusion

As you can see above, the Subfolder directory was not transferred. You can also exclude files with this: just type its name down in quotes.

To stop multiple similar files/folders from being transferred, use the * symbol with the –exclude option. This acts as a substitute for any other file name.

rsync -ruv --exclude '*.txt' ~/Source-Folder/ ~/Copy-Folder

rsync pattern exclusion

This command meant that rsync ignored all files that ended with .TXT and only copied along a folder. The * symbol acts as a wildcard — it represents all the potential words and letters you could, in this example, name a TXT file. This is a basic exclusion pattern for rsync.

There is something important you should know about exclusions: they are located relative to your copy source! Put simply, you need to tell rsync the position of the files you are excluding in relation to where you chose to copy your files. Here’s an example of this in play:

rsync specific exclusion

Since we are copying data from the Source-Folder directory, we don’t need to specify where exactly the Subfolder directory is located. It’s right inside it. However, if we then want to exclude File-1.txt from inside that folder, we need to state its location, with the ‘Source-Folder’ directory as its root. Keep this in mind if you find your exclusions failing!

Making Backups Faster With rsync

As previously stated, rsync has the ability to compress the files it copies, then decompress them at the other end. This is meant to reduce the amount of data transfer required to copy a file, trading time for the CPU usage needed for compression. So if you’re on a laptop and want to save some battery life


Easily Increase Your Battery Life With TLP for Linux




Easily Increase Your Battery Life With TLP for Linux

Linux tends to guzzle up more battery life than Windows, even though most Linux installations are lighter than Windows on system resources. Why is that?
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, you may not want to use this.

rsync -ruv -z ~/Source-Folder/ ~/Copy-Folder

rsync compression

All we’re doing here is adding the -z option to rsync: this represents the compression option. It’s short for zlib, which is the software rsync uses to do this. Essentially (pun intended) it zips your files from one place to another.

To see the improvements in transfer speeds, simply look at rsync’s output. More specifically, the “speedup is [x]” (measured in seconds). Use this as a gauge to whether or not compressing your file backups is worth it to you. Every computer is different!

Testing the Waters

Before leaping in the deep end and using rsync proper, it’s always good to make a dry run first. Doing this allows you to see exactly what rsync will copy and where, before the data is backed up. All you need is to add the -n option (short for “no changes made“) to your command to do a test run:

rsync -ruv -n ~/Source-Folder/ ~/Copy-Folder

rsync dry run

As the above image indicates, no files are actually transferred. However, you still get to see what would have happened if you left out the -n option. Because of this, a dry run in rsync is an extremely fast and easy precautionary step to take, especially if you’re using a lot of options chained together.

Going Further

Hopefully, this article has provided you with the know-how necessary to back up your data quickly and efficiently from the command-line. However, rsync is an extremely versatile tool, so if you find your backup needs exceed that of this guide


How to Make Data Backups on Ubuntu & Other Distros




How to Make Data Backups on Ubuntu & Other Distros

How much sensitive data would you lose if your disk drive died? Naturally, you need a backup solution, but making backups in Linux can be tricky if you don’t know what you’re doing…
Read More

, don’t be afraid to enter this command:

man rsync

rsync manual

The document you see goes through all the options covered here in much more detail, along with many others. For example, it explains how to exclude files by their size, useful for filtering out blank or redundant files.

Do you prefer using the command line to back up your data? Why or why not?

via MakeUseOf.com
Back Up Your Data With Rsync (No Desktop Required)

What we can learn from the OSU terrorist attack

by Greg Ellifritz

On November 28, an Islamic terrorist attacked students at the Ohio State University using both his vehicle and a butcher knife. Eleven students were injured. Fortunately none were killed.

If you haven’t heard about the attack, check out this article for a brief summary. The terrorist drove his car over the curb and struck six students who were outside a classroom after evacuating from a fire alarm. When his car was disabled, he got out of the car and cut five more students with a butcher knife. An OSU police officer happened to be very close by and responded immediately to the incident, shooting the terrorist and killing him. You can read an eyewitness account here.

This attack has a personal connection for me. I graduated from OSU (twice) and currently work for a community that borders the campus. That morning, OSU police called neighboring agencies for mutual aid. Four officers from my department responded. I was called into work early in the event additional officers were needed. They didn’t end up needing more people, so I spent the morning listening to the events unfold on the police radios in my cruiser.

In the last couple weeks since the incident, I have spoken with our officers on the scene as well as members of OSU’s police department and some Columbus police officers who were on the scene. The information I share comes from officers involved in the incident, but is not classified in any way.

First of all, there are some who doubt this was a terrorist attack, instead thinking that it was a mentally ill kid who did the killing. That is categorically untrue. ISIS formally claimed responsibility for the attack.

The Clarion Project looked at the terrorist’s Facebook page immediately before the attack and noted the following:

“In a Facebook post shortly before launching Monday’s stabbing attack, Artan denounced American foreign policy and called on Washington “to stop interfering with other countries, especially the Muslim Ummah.”

“By Allah, we will not let you sleep unless you give peace to the Muslims. You will not celebrate or enjoy any holiday,” he added, according to CNN.

He also praised American born Al-Qaeda cleric Anwar al-Awlaki, whose online propaganda sermons have been linked to the radicalization of a number of terrorists worldwide.”

This was clearly a terrorist attack and not the work of a lone mentally ill student.

Why it happened and why we can expect more attacks in the future.

What many people don’t understand is that Western Civilization is under a coordinated attack by Islamic Terrorists. The terrorists’ ultimate goal is to establish a world where Sharia law is enforced everywhere. The terrorists tell us what they want and how they are going to accomplish their goal. Very few people actually listen.

According to the terrorist publication Dabiq, the attacks are explicitly designed to create discord between Muslims and members of other religions. The Intercept describes this tactic as follows:

“The attack had “further [brought] division to the world,” the group said, boasting that it had polarized society and “eliminated the grayzone,” representing coexistence between religious groups. As a result, it said, Muslims living in the West would soon no longer be welcome in their own societies. Treated with increasing suspicion, distrust and hostility by their fellow citizens as a result of the deadly shooting, Western Muslims would soon be forced to “either apostatize … or they [migrate] to the Islamic State, and thereby escape persecution from the crusader governments and citizens,” the group stated, while threatening of more attacks to come.”

“Through murderous provocation, the Islamic State seeks to trigger a civilizational war between Muslims and the West, violently dragging both parties into such a battle if need be.”

This is the PUBLICLY ANNOUNCED STRATEGY of Islamic terrorism, yet people refuse to accept we are in a war with Islamic radicals.

Don’t believe it? Read the Atlantic’s article What ISIS Really Wants. It’s a long article, but will give you a tremendous amount of background information about Islamic terrorism and what the terrorists see as plans for the future. Some highlights:

“Following takfiri doctrine, the Islamic State is committed to purifying the world by killing vast numbers of people. The lack of objective reporting from its territory makes the true extent of the slaughter unknowable, but social-media posts from the region suggest that individual executions happen more or less continually, and mass executions every few weeks. Muslim “apostates” are the most common victims. Exempted from automatic execution, it appears, are Christians who do not resist their new government. Baghdadi permits them to live, as long as they pay a special tax, known as the jizya, and acknowledge their subjugation. The Koranic authority for this practice is not in dispute.”

” In Haykel’s estimation, the fighters of the Islamic State are authentic throwbacks to early Islam and are faithfully reproducing its norms of war. This behavior includes a number of practices that modern Muslims tend to prefer not to acknowledge as integral to their sacred texts. “Slavery, crucifixion, and beheadings are not something that freakish [jihadists] are cherry-picking from the medieval tradition,” Haykel said. Islamic State fighters “are smack in the middle of the medieval tradition and are bringing it wholesale into the present day.”

“Nonetheless, the caliphate has continued to embrace slavery and crucifixion without apology. “We will conquer your Rome, break your crosses, and enslave your women,” Adnani, the spokesman, promised in one of his periodic valentines to the West. “If we do not reach that time, then our children and grandchildren will reach it, and they will sell your sons as slaves at the slave market.”

“Choudary took pains to present the laws of war under which the Islamic State operates as policies of mercy rather than of brutality. He told me the state has an obligation to terrorize its enemies—a holy order to scare the shit out of them with beheadings and crucifixions and enslavement of women and children, because doing so hastens victory and avoids prolonged conflict.”

These attacks will not end. We will see more and more of them as the ISIS propagandists inspire and radicalize more of these “lone wolf” terrorists.

Why Vehicles and Knives?

Besides the obvious reasons regarding ease of access, these weapons are a terrorist favorite because they are what ISIS leaders tell them to use! Did you know that ISIS has several online magazines and websites providing instruction to terrorists wanting to attack the West?

One of the terrorist propaganda outlets is the online magazine called Rumiyah. According to this article, the most recent edition of Rumiyah directs terrorists to use vehicles as weapons:

“The latest issue of Rumiyah, a new magazine from the terror group aimed at English-language speakers, included an article titled “Just Terror Tactics” that outlined ideal vehicles to use in terror attacks as well as ideal targets.

“Though being an essential part of modern life, very few actually comprehend the deadly and destructive capability of the motor vehicle and its capacity of reaping large numbers of casualties if used in a premeditated manner,” the article said.

The article also cited the attack in Nice, France, in July, in which a supposed ISIS supporter killed 86 people by plowing into a crowd with a truck on Bastille Day.

“Vehicles are like knives, as they are extremely easy to acquire,” the article said.”

The same issue of Rumiyah also advises terrorists about using blades as weapons. This article describes the advice:

“In the latest PDF edition, which has been distributed widely on social media, supporters were urged to arm themselves with readily-available weapons and launch a ‘campaign of knife attacks’ in which the attacker ‘could dispose of his weapon after each use, finding no difficulty in acquiring another one.’

In a call to arms, an article in the magazine says: ‘One need not be a military expert or a martial arts master, or even own a gun or rifle in order to carry out a massacre or to kill and injure several disbelievers and terrorize an entire nation.’

Urging followers to carry out brutal acts of violence, the article continues: ‘Many people are often squeamish of the thought of plunging a sharp object into another person’s flesh. “

“It is a discomfort caused by the untamed, inherent dislike for pain and death, especially after ‘modernization’ distanced males from partaking in the slaughtering of livestock for food and the striking of the enemy in war.

‘However, any such squirms and discomforts are never an excuse for abandoning jihad.’

The shocking article even goes on to advise would-be terrorists on which weapons to use.

‘It is explicitly advised not to use kitchen knives, as their basic structure is not designed to handle the kind of vigorous application used for assassinations and slaughter,’ it reads, adding: ‘to avoid troublesome knives, those that can cause harm to the user because of poor manufacturing.’ “

Is it any wonder that the OSU terror suspect used his vehicle and a knife? That’s what the ISIS leadership told him to use! Think about the recent truck attack in Nice, France and the recent shopping mall knife attack in Minnesota. These terrorists were inspired and instructed by the same sources.

Both Dabiq and Rumiyah are open source magazines and easily found online. I will not link to them here (instead linking to other articles describing the texts) because I don’t want to give them more web traffic. I also urge my readers to exercise caution when visiting sites like these because they are undoubtedly being monitored by our intelligence agencies. You probably don’t want to end up on that list.

It is important, however, to be aware of what the terrorist leadership is advocating. The terrorists are publishing their playbook. They are telling us exactly what they are planning, yet few Americans can be bothered to study terrorist tactics. We need to be smarter than that. Do your homework and study your enemy if you want to prevail in this inevitable battle.

Issues specific to the OSU attack

1) Be careful when the fire alarm is triggered. Recognize that numerous terrorists and active killers have exploited victims’ actions after fire alarms are activated. When the alarm goes off, large groups of people congregate in very predictable locations, making them easy victims of a terrorist attack.

According to sources at OSU, it seems that this terrorist did not pull the fire alarm himself. It appears to be a crime of opportunity. The terrorist saw a large group of people close to the road and decided to attack.

When the fire alarm is pulled in a public building, be ready for anything. It might be an active killer attack. Don’t go to predictable evacuation locations. Don’t evacuate to a parking lot. Stay away from any location where large groups of people are physically close to a roadway open to vehicular traffic. Be alert as you evacuate.

2) Callers reporting the terrorist act overwhelmed the police/medical dispatch system. This isn’t the fault of OSU. All terrorist attacks everywhere overwhelm dispatching resources. More than 1000 phone calls were fielded by four police dispatchers in the one-hour time period following the attack. Many of those callers provided bad information that misdirected responding officers.

Several people reported there was a second attacker (a male armed with a rifle) who fled the scene. No such person actually existed. Five SWAT teams were mobilized based on these reports. The teams spent nearly two hours searching buildings and parking garages where the mystery man with the rifle was supposedly located. It was a colossal waste of time and manpower.

It seems self evident, but you shouldn’t call police in a crisis situation if you don’t have importantly information to share. Get GOOD descriptions of offenders. Concentrate on the person’s sex, age, hair color, clothing color, direction of travel, and vehicle description. If you don’t have this kind of information. don’t call 911! Let the dispatchers focus on people who have the most useful information to share.

You should also avoid sharing second or third hand information with police on the scene. If you didn’t see it, don’t report it. Like the “telephone game” repeated information quickly becomes inaccurate and wastes valuable resources.

3) Prepare for non-typical terrorist attacks. Not every terrorist attack is going to be conducted with bombs and guns. You must be ready to deal with vehicles, knives, fire, or anything else the terrorists can come up with on the battlefield. Expect the unexpected.

The terrorists are deliberately targeting areas where there are lots of defenseless victims. If no one can fight back, the killer gets a much higher body count. If you visit or work in “gun free” zones (and obey the law) you won’t be armed with your pistol to stop the attack. How good are your empty hand skills? Can you evade or disarm a knife-wielding attacker? Do you know how to use your own knife to incapacitate a terrorist?

If you are truly concerned about your survival, you should probably invest in a few empty hand or knife classes instead of taking another “run and gun” carbine class.

4) Medical skills are important to have. Officers at the scene stated that there were 11 injured people at the attack site along with a whole bunch of student onlookers. No one provided any type of medical care to the injured people until the cops and medics showed up. Eleven serious injuries and none of the bystanders even considered doing something to save the injured people’s lives?

Fortunately, the lack of first aid at the scene didn’t cost anyone his life. This occurred in a big city with a very fast police and fire response time. If the medics were fewer in number or had to travel a large distance to get to the scene, some of those victims could have bled to death.

You must get some quality medical training. I teach quite a few battlefield medicine classes every year. You can check out my schedule here. If you can’t train with me, take a class from either Dark Angel Medical or Lone Star Medics. I’m friends with the guys who own both companies and have taken training classes from both. They are top notch medics and instructors. Having the skills they are teaching may mean the difference between life and death if you get caught up in a terrorist attack like this one. If you can’t make it to a good medical class, at least read my article Field Medicine for Terrorist Attacks to familiarize yourself with the concepts involved in treating a knife, gunshot, or blast injury.

Folks, these attacks are not going to stop anytime soon. Recognize that and take the steps necessary to ensure your own safety.

Greg Ellifritz is the full time firearms and defensive tactics training officer for a central Ohio police department. He holds instructor or master instructor certifications in more than 75 different weapon systems, defensive tactics programs and police specialty areas. Greg has a master’s degree in Public Policy and Management and is an instructor for both the Ohio Peace Officer’s Training Academy and the Tactical Defense Institute.

For more information or to contact Greg, visit his training site at Active Response Training.


via Buckeye Firearms Association
What we can learn from the OSU terrorist attack

MySQL Group Replication and table design

Today’s article is about the first two restrictions in the requirements page of the manual:

  • InnoDB Storage Engine: data must be stored in the InnoDB transactional storage engine.
  • Primary Keys: every table that is to be replicated by the group must have an explicit primary key defined.

So the first requirement is easy to check by a simple query that list all the non InnoDB tables:

SELECT table_schema, table_name, engine, table_rows, 
       (index_length+data_length)/1024/1024 AS sizeMB 
FROM information_schema.tables 
WHERE engine != 'innodb' 
  AND table_schema NOT IN 
    ('information_schema', 'mysql', 'performance_schema');

The second one is a bit more tricky. Let me show you first how Group Replication behaves:

Case 1: no keys

Let’s create a table with no Primary Key (neither any other keys) and then let’s insert one record:

mysql> create table test_tbl_nopk (id int, name varchar(10));
mysql> insert into test_tbl_nopk values (1,'lefred');
ERROR 3098 (HY000): The table does not comply with the requirements by an external plugin.

And in the error log we can see:

[ERROR] Plugin group_replication reported: 'Table test_tbl_nopk does not have any PRIMARY KEY. 
             This is not compatible with Group Replication'

So far, so good as it’s what we were expecting, right ?

Case 2: no PK, but NOT NULL UNIQUE KEY

Now, if you know InnoDB, when there is no PK defined, InnoDB will use the first NOT NULL UNIQUE KEY as PK. How will Group Replication handle that ?
Let’s verify:

mysql> create table test_tbl_nopk_uniq_notnull (id int not null unique key, name varchar(10));
mysql> insert into test_tbl_nopk_uniq_notnull values (1,'lefred');
Query OK, 1 row affected (0.01 sec)

Excellent, so Group Replication behaves like InnoDB and allows NOT NULL UNIQUE KEYS.

Case 3: no PK, but NULL UNIQUE KEY

Just to verify, let’s try with a UNIQUE KEY that can be NULL too:

mysql> create table test_tbl_nopk_uniq_null (id int unique key, name varchar(10));
mysql> insert into test_tbl_nopk_uniq_null values (1,'lefred');
ERROR 3098 (HY000): The table does not comply with the requirements by an external plugin.

This works then as expected. Why that ? Because, in InnoDB when no primary key is defined, the first unique not null key is used as seen above, but if none
is available, InnoDB will create a hidden primary key (stored on 6 bytes). The problem with such key is that this value is global to all InnoDB tables without
PK (this can of course cause contention), but in the case of Group Replication, there is no guarantee that this hidden PK will be the same on the other nodes that are members of the Group. That’s why this is not supported.

Conclusion

So if you want to know if you have tables without valid key design for Group Replication, please run the following statement:

SELECT tables.table_schema , tables.table_name , tables.engine 
FROM information_schema.tables 
LEFT JOIN ( 
   SELECT table_schema , table_name 
   FROM information_schema.statistics 
   GROUP BY table_schema, table_name, index_name HAVING 
     SUM( case when non_unique = 0 and nullable != 'YES' then 1 else 0 end ) = count(*) ) puks 
 ON tables.table_schema = puks.table_schema and tables.table_name = puks.table_name 
 WHERE puks.table_name is null 
   AND tables.table_type = 'BASE TABLE' AND Engine="InnoDB";

The query above is the courtesy of Roland Bouman.

via Planet MySQL
MySQL Group Replication and table design