Horizon Setup V2 5 3 0 22
Zee Badoni
After publishing Horizon's assets, its primary configuration file will be located at config/horizon.php. This configuration file allows you to configure the queue worker options for your application. Each configuration option includes a description of its purpose, so be sure to thoroughly explore this file.
Warning
Horizon uses a Redis connection named horizon internally. This Redis connection name is reserved and should not be assigned to another Redis connection in the database.php configuration file or as the value of the use option in the horizon.php configuration file.
Horizon exposes a dashboard at the /horizon URI. By default, you will only be able to access this dashboard in the local environment. However, within your app/Providers/HorizonServiceProvider.php file, there is an authorization gate definition. This authorization gate controls access to Horizon in non-local environments. You are free to modify this gate as needed to restrict access to your Horizon installation:
Sometimes, you may not be interested in viewing certain jobs dispatched by your application or third-party packages. Instead of these jobs taking up space in your "Completed Jobs" list, you can silence them. To get started, add the job's class name to the silenced configuration option in your application's horizon configuration file:
Once you have configured your supervisors and workers in your application's config/horizon.php configuration file, you may start Horizon using the horizon Artisan command. This single command will start all of the configured worker processes for the current environment:
When you're ready to deploy Horizon to your application's actual server, you should configure a process monitor to monitor the php artisan horizon command and restart it if it exits unexpectedly. Don't worry, we'll discuss how to install a process monitor below.
Supervisor is a process monitor for the Linux operating system and will automatically restart your horizon process if it stops executing. To install Supervisor on Ubuntu, you may use the following command. If you are not using Ubuntu, you can likely install Supervisor using your operating system's package manager:
Supervisor configuration files are typically stored within your server's /etc/supervisor/conf.d directory. Within this directory, you may create any number of configuration files that instruct supervisor how your processes should be monitored. For example, let's create a horizon.conf file that starts and monitors a horizon process:
You may configure how many seconds are considered a "long wait" within your application's config/horizon.php configuration file. The waits configuration option within this file allows you to control the long wait threshold for each connection / queue combination. Any undefined connection / queue combinations will default to a long wait threshold of 60 seconds:
The horizon is the apparent curve that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This curve divides all viewing directions based on whether it intersects the relevant body's surface or not.
The true horizon is a theoretical line, which can only be observed to any degree of accuracy when it lies along a relatively smooth surface such as that of Earth's oceans. At many locations, this line is obscured by terrain, and on Earth it can also be obscured by life forms such as trees and/or human constructs such as buildings. The resulting intersection of such obstructions with the sky is called the visible horizon. On Earth, when looking at a sea from a shore, the part of the sea closest to the horizon is called the offing.[1]
The true horizon surrounds the observer and it is typically assumed to be a circle, drawn on the surface of a perfectly spherical model of the relevant celestial body, i.e., a small circle of the local osculating sphere. With respect to Earth, the center of the true horizon is below the observer and below sea level. Its radius or horizontal distance from the observer varies slightly from day to day due to atmospheric refraction, which is greatly affected by weather conditions. Also, the higher the observer's eyes are from sea level, the farther away the horizon is from the observer. For instance, in standard atmospheric conditions, for an observer with eye level above sea level by 1.70 metres (5 ft 7 in), the horizon is at a distance of about 5 kilometres (3.1 mi).[2]When observed from very high standpoints, such as a space station, the horizon is much farther away and it encompasses a much larger area of Earth's surface. In this case, the horizon would no longer be a perfect circle, not even a plane curve such as an ellipse, especially when the observer is above the equator, as the Earth's surface can be better modeled as an oblate ellipsoid than as a sphere.
The word horizon derives from the Greek ὁρίζων κύκλος (horízōn kýklos) 'separating circle',[3] where ὁρίζων is from the verb ὁρίζω (horízō) 'to divide, to separate',[4] which in turn derives from ὅρος (hóros) 'boundary, landmark'.[5]
Historically, the distance to the visible horizon has long been vital to survival and successful navigation, especially at sea, because it determined an observer's maximum range of vision and thus of communication, with all the obvious consequences for safety and the transmission of information that this range implied. This importance lessened with the development of the radio and the telegraph, but even today, when flying an aircraft under visual flight rules, a technique called attitude flying is used to control the aircraft, where the pilot uses the visual relationship between the aircraft's nose and the horizon to control the aircraft. Pilots can also retain their spatial orientation by referring to the horizon.
In many contexts, especially perspective drawing, the curvature of the Earth is disregarded and the horizon is considered the theoretical line to which points on any horizontal plane converge (when projected onto the picture plane) as their distance from the observer increases. For observers near sea level, the difference between this geometrical horizon (which assumes a perfectly flat, infinite ground plane) and the true horizon (which assumes a spherical Earth surface) is imperceptible to the unaided eye. However, for someone on a 1,000 m (3,300 ft) hill looking out across the sea, the true horizon will be about a degree below a horizontal line.
In astronomy, the horizon is the horizontal plane through the eyes of the observer. It is the fundamental plane of the horizontal coordinate system, the locus of points that have an altitude of zero degrees. While similar in ways to the geometrical horizon, in this context a horizon may be considered to be a plane in space, rather than a line on a picture plane.
On terrestrial planets and other solid celestial bodies with negligible atmospheric effects, the distance to the horizon for a "standard observer" varies as the square root of the planet's radius.[citation needed] Thus, the horizon on Mercury is 62% as far away from the observer as it is on Earth, on Mars the figure is 73%, on the Moon the figure is 52%, on Mimas the figure is 18%, and so on.
The same equation can also be derived using the Pythagorean theorem.At the horizon, the line of sight is a tangent to the Earth and is also perpendicular to Earth's radius. This sets up a right triangle, with the sum of the radius and the height as the hypotenuse. With
where R is the radius of the Earth (R and h must be in the same units). For example,if a satellite is at a height of 2000 km, the distance to the horizon is 5,430 kilometres (3,370 mi);neglecting the second term in parentheses would give a distance of 5,048 kilometres (3,137 mi), a 7% error.
Another relationship involves the great-circle distance s along the arc over the curved surface of the Earth to the horizon; this is more directly comparable to the geographical distance on a map.
When the observer is elevated, the horizon zenith angle can be greater than 90. The maximum visible zenith angle occurs when the ray is tangent to Earth's surface; from triangle OCG in the figure at right,
where h \displaystyle h is the observer's height above the surface and γ \displaystyle \gamma is the angular dip of the horizon. It is related to the horizon zenith angle z \displaystyle z by:
For example, for an observer B with a height of hB=1.70 m standing on the ground, the horizon is DB=4.65 km away. For a tower with a height of hL=100 m, the horizon distance is DL=35.7 km. Thus an observer on a beach can see the top of the tower as long as it is not more than DBL=40.35 km away. Conversely, if an observer on a boat (hB=1.7 m) can just see the tops of trees on a nearby shore (hL=10 m), the trees are probably about DBL=16 km away.
It is similarly possible to calculate how much of a distant object is visible above the horizon. Suppose an observer's eye is 10 metres above sea level, and he is watching a ship that is 20 km away. His horizon is:
Due to atmospheric refraction the distance to the visible horizon is further than the distance based on a simple geometric calculation. If the ground (or water) surface is colder than the air above it, a cold, dense layer of air forms close to the surface, causing light to be refracted downward as it travels, and therefore, to some extent, to go around the curvature of the Earth. The reverse happens if the ground is hotter than the air above it, as often happens in deserts, producing mirages. As an approximate compensation for refraction, surveyors measuring distances longer than 100 meters subtract 14% from the calculated curvature error and ensure lines of sight are at least 1.5 metres from the ground, to reduce random errors created by refraction.
aa06259810