Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
From: "Steinmaurer, Thomas" <thomas.steinmaurer@dynatrace.com>
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
Subject: RE: space left for compaction
Thread-Topic: space left for compaction
Thread-Index: AQHTOcUVy/FGVaG9tUGHd49ORqS0uaLOrJOw
Date: Sun, 1 Oct 2017 08:38:55 +0000
Message-ID: <MWHPR05MB300558692403A9E554AF437F9D7C0@MWHPR05MB3005.namprd05.prod.outlook.com>
References: <tencent_FF082E1EEDD5920CB5B142FF42AA4D74B309@qq.com>
In-Reply-To: <tencent_FF082E1EEDD5920CB5B142FF42AA4D74B309@qq.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: dynatrace.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: multipart/alternative;
	boundary="_000_MWHPR05MB300558692403A9E554AF437F9D7C0MWHPR05MB3005namp_"
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Oct 2017 08:38:55.5719
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 70ebe3a3-5b30-435d-9d67-7716d74ca190
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR05MB3006
archived-at: Sun, 01 Oct 2017 08:39:11 -0000

--_000_MWHPR05MB300558692403A9E554AF437F9D7C0MWHPR05MB3005namp_
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

Hi,

half of free space does not make sense. Imagine your SSTables need 100G spa=
ce and you have 20G free disk. Compaction won't be able to do its job with =
10G.

Half free of total disk makes more sense and is what you need for a major c=
ompaction worst case.

Thomas

From: Peng Xiao [mailto:2535053@qq.com]
Sent: Samstag, 30. September 2017 10:21
To: user <user@cassandra.apache.org>
Subject: space left for compaction

Dear All,

As for STCS,datastax suggest us to keep half of the free space for compacti=
on,this is not strict,could anyone advise how many space should we left for=
 one node?

Thanks,
Peng Xiao
The contents of this e-mail are intended for the named addressee only. It c=
ontains information that may be confidential. Unless you are the named addr=
essee or an authorized designee, you may not copy or use it, or disclose it=
 to anyone else. If you received it in error please notify us immediately a=
nd then destroy it. Dynatrace Austria GmbH (registration number FN 91482h) =
is a company registered in Linz whose registered office is at 4040 Linz, Au=
stria, Freist?dterstra?e 313

--_000_MWHPR05MB300558692403A9E554AF437F9D7C0MWHPR05MB3005namp_
Content-Type: text/html; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

<html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-micr=
osoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http:=
//www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dus-ascii"=
>
<meta name=3D"Generator" content=3D"Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
	{font-family:"Cambria Math";
	panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
	{font-family:Calibri;
	panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
	{margin:0cm;
	margin-bottom:.0001pt;
	font-size:12.0pt;
	font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
	{mso-style-priority:99;
	color:#0563C1;
	text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
	{mso-style-priority:99;
	color:#954F72;
	text-decoration:underline;}
span.EmailStyle17
	{mso-style-type:personal-reply;
	font-family:"Calibri",sans-serif;
	color:#1F497D;}
.MsoChpDefault
	{mso-style-type:export-only;
	font-family:"Calibri",sans-serif;
	mso-fareast-language:EN-US;}
@page WordSection1
	{size:612.0pt 792.0pt;
	margin:70.85pt 70.85pt 2.0cm 70.85pt;}
div.WordSection1
	{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext=3D"edit">
<o:idmap v:ext=3D"edit" data=3D"1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=3D"DE-AT" link=3D"#0563C1" vlink=3D"#954F72">
<div class=3D"WordSection1">
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:&quot;Ca=
libri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN-US">Hi,<o:p></=
o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:&quot;Ca=
libri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p>&nbsp=
;</o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:11.0pt;font-=
family:&quot;Calibri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN=
-US">half of free space does not make sense. Imagine your SSTables need 100=
G space and you have 20G free disk. Compaction won&#8217;t
 be able to do its job with 10G.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:11.0pt;font-=
family:&quot;Calibri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN=
-US"><o:p>&nbsp;</o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:11.0pt;font-=
family:&quot;Calibri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN=
-US">Half free of total disk makes more sense and is what you need for a ma=
jor compaction worst case.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:11.0pt;font-=
family:&quot;Calibri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN=
-US"><o:p>&nbsp;</o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:11.0pt;font-=
family:&quot;Calibri&quot;,sans-serif;color:#1F497D;mso-fareast-language:EN=
-US">Thomas</span><span style=3D"font-size:11.0pt;font-family:&quot;Calibri=
&quot;,sans-serif;color:#1F497D"><o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"mso-fareast-language:EN-US"><o:p>&nbs=
p;</o:p></span></p>
<p class=3D"MsoNormal"><b><span lang=3D"EN-US" style=3D"font-size:11.0pt;fo=
nt-family:&quot;Calibri&quot;,sans-serif">From:</span></b><span lang=3D"EN-=
US" style=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,sans-serif"> =
Peng Xiao [mailto:2535053@qq.com]
<br>
<b>Sent:</b> Samstag, 30. September 2017 10:21<br>
<b>To:</b> user &lt;user@cassandra.apache.org&gt;<br>
<b>Subject:</b> space left for compaction<o:p></o:p></span></p>
<p class=3D"MsoNormal"><o:p>&nbsp;</o:p></p>
<div>
<p class=3D"MsoNormal">Dear All,<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class=3D"MsoNormal">As for STCS,datastax suggest us to keep half of the =
free space for compaction,this is not strict,could anyone advise how many s=
pace should we left for one node?<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Thanks,<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Peng Xiao<o:p></o:p></p>
</div>
</div>
The contents of this e-mail are intended for the named addressee only. It c=
ontains information that may be confidential. Unless you are the named addr=
essee or an authorized designee, you may not copy or use it, or disclose it=
 to anyone else. If you received
 it in error please notify us immediately and then destroy it. Dynatrace Au=
stria GmbH (registration number FN 91482h) is a company registered in Linz =
whose registered office is at 4040 Linz, Austria, Freist&auml;dterstra&szli=
g;e 313
</body>
</html>

--_000_MWHPR05MB300558692403A9E554AF437F9D7C0MWHPR05MB3005namp_--